Granted: It's impossible to think of Berlin without thinking first of the Wall.

The first time I saw Berlin, more than 15 years ago, the Wall was the first stop on my junior-year-abroad group's tour of the city, its political message the most important thing Berlin had to offer a group of impressionable young Americans off to see the world.

Today, it's still the city's inescapable symbol and its most potent tourist attraction. But if the Wall represents Berlin, Berlin, most emphatically, is not merely the Wall.

The Berliners have a saying, Berlin bleibt immer Berlin -- Berlin will always be Berlin -- and today, 750 years after its birth, the city is living resolutely up to the motto. West Berlin, at least, is back to the old exhilarating form that made the city a cultural mecca in the early decades of the century -- a place of flash and allure, fast- moving and multilayered, a little raucous at times, highly refined at others, but always palpably exciting and challenging to the visitor willing to learn a little and enjoy himself a lot.

Celebrating its anniversary this summer and fall, the city is touting itself with star-studded galas, fireworks and visits to West Berlin by such heads of state as Ronald Reagan. The city, masked in heavy scaffolding most of last year, has enjoyed a general sprucing up that has finally wiped the postwar grime off many major public buildings and restored the graceful elegance of the art nouveau fac ades along the main thoroughfare of the Kurfuersten- damm. In East Berlin, a more subdued celebration will emphasize the performing arts.

All the pageantry is stressing Berlin's talent for rebirth and resilience as much as its complex history, marking its reentry into the front ranks of major-draw world cities as much as remembering the division that keeps it on the front lines of world politics. The city's size and eclecticism, its unique blend of the highly urban, the peacefully rural and the sylvan, all coexisting on a piece of Prussian plain deliberately demarcated by the steel and concrete Wall, will be on vivid display.

Most people forget, or don't realize, that Berlin lies deep in East German territory, more than 100 miles from the West German border. Approaching planes fly in low, at an altitude of about 10,000 feet, and you can see, in some places, where the flat East German countryside runs into the Wall, which totally surrounds West Berlin.

Inside the Wall, rural farmland and green forests dotted with lakes continue for a while, then give way quite suddenly to the urban sprawl that is contemporary Berlin -- modern high-rises mixing with bungalows in the residential districts, smokestacks and signs of industry and commerce rubbing elbows with sleek office buildings and turn-of-the-century apartment houses downtown, everywhere a tangled web of streets packed with cars and pedestrians. Atop one tall glass office building, the Mercedes-Benz symbol stands out boldly against the sky, no surer sign of modern western living.

For a few brief moments, the plane dips once more across the Wall and its death strip, where they cut through the heart of the city, and flies low over drab downtown East Berlin, passing the gray, spacelike television tower on the Alexanderplatz and the seedy shoe box socialist architecture surrounding it, then past the lonely, neglected Brandenburg Gate. Then it's back in West Berlin, just like that, where the congestion and the color all along the Kurfuerstendamm signal excitement and up-to-dateness once again.

In fact, the Ku'damm, as this fashionable promenade of West Berlin is popularly (and pragmatically) known, is the center of pilgrimage for today's tourists to Berlin, more so than the Wall. The life of the city throbs around the ruins of the Kaiser Wilhelm Memorial Church, so gleaming and polished it's undoubtedly the best kept ruin the world, and its surrounding square, where the mix of humanity reflects the diversity that is Berlin.

Out-of-date punkers and hippies mix with chic teen-agers, Turkish guest workers are as ubiquitous as businessmen in three-piece suits, mothers pushing strollers make room for Hare Krishnas weaving their way down the road.

The famed tolerance of Berlin, Germany's only nonprovincial city, is on open display here. Antinuclear or environmental activists conduct petition drives and hand out flyers; amateur musicians try out their wings and collect a few pfennigs for their efforts; panhandlers ply their trade. Meanwhile, street artists, the surest sign of summer in Berlin, emerge in fine weather to draw your portrait for a mere 5 to 10 marks ($2 to $5), and some of them are surprisingly good.

Along the Ku'damm and the Tauentzienstrasse that is its extension, glitzy and expensive shops offering everything from shoes, high-fashion clothes and leather goods to jewelry, books and antiques are a window-shopper's paradise. At the end of the line sits the crown jewel, KaDeWe (short for Kaufhaus des Westens), the biggest department store on the Continent, groaning with goods.

It's as much of a tourist attraction as anything else in Berlin, especially its famous food halls, which are always described as rivaling those of London's Harrods -- although, for floor space and capacity to confuse, I think it's a tossup. KaDeWe may actually be, however, one of the few places where you'll see whole sides of venison and wild boar hanging over the butcher's counter and fresh lion meat on sale for the discerning carnivore.

But most vital to the two-mile-long Ku'damm, with its broad sidewalks and eclectic mix of elegant art nouveau houses and modern, neon-lit, stacked-glass monstrosities, are the 200 cafe's, restaurants and Kneipen, or pubs, that it hosts. Sidewalk cafe'-sitting is as highly refined an art in Berlin as it is in Paris, and I never feel I'm in Berlin until I've sat for an afternoon on a sidewalk in the sun, sipping espresso or a pink Berliner Weisse (wheat beer with a shot of raspberry syrup) and watched the world, and the day, go by.

You can take your pick from classic, old-world locales directly on the Ku'damm, such as Cafe' Moehring and Cafe' Kranzler; or the cafe' in the fabled Hotel Kempinski that evokes the dreamy, elegant atmosphere of prewar Berlin, while you enjoy your very traditional Kaffee und Kuchen (coffee and cake); or venture off the Ku into the side streets, where trendier spots have sprung up and a more playful ambiance prevails.

Off the Savigny and Stuttgart squares are dozens of slick, trendy Kneipen and cafe's that are frequented by the Berlin Schickeria, the young and moneyed crowd. Dralle is a take-off on a '50s-style soda fountain, complete with red formica-topped tables; Der Klo may be the only pub in the world with a lavatory theme.

The advent of so many flashy new places in the course of the '80s has upset some longtime Berliners, who feel the character of their city is becoming compromised. "They're turning everything into these schincky-micky places and wiping out so much of the good old Berlin," grumbled a friend on my most recent visit, last December. He had just watched his favorite restaurant haunt ("a slow and easy kind of place, no fancy food or anything") shut down for six months and reopen completely remodeled as an upscale bistro for the slick crowd.

But Berlin wouldn't be Berlin unless it was trendy, unless it was busy catching the latest continental drifts and imbuing them with its own distinct and original flavor. At all times and at every level, Berlin has something for everyone.

If you're a culture buff, there are dozens of major museums to visit, including the National Gallery (Berlin's museum of modern art), the Dahlem museum complex and the Egyptian museum, with its famous bust of Queen Nefertiti. There are scores of art galleries, theaters (such as the Schaubuehne and Theater des Westens), movie houses and concert halls -- from the Deutsche Oper to the Philharmonic -- to keep you going from dawn to dusk. If you're a history buff, there's the Charlottenburg Palace, the Reichstag, the Olympic Stadium, Spandau Prison (just waiting for Rudolf Hess, its only inmate, to die before it is torn down) and all of East Berlin to explore.

If you're an entertainment maniac and a night owl, welcome to the city that never sleeps -- high-steppers can take their pick from hundreds of nightspots featuring everything from jazz to rock to salsa, or maybe just a quiet piano, if you'd prefer.

If you like to dance, try the Far-Out discotheque run by the devotees of lately defiled Bhagwan Shree Rajneesh -- it's all white, slick and shining, with a huge dance floor and lots of mirrors, and rajneshires running around in their orange clothes embracing each other fervently. (The thing to do is to dance alone, blissfully inattentive to the hundreds of bodies surrounding you.) Slightly classier but no more trendy is Der Dschungel (The Jungle), where the young and beautiful congregate.

And if you'd like to sample a bit of Berlin's famed, if faded, decadence, there are still any number of transvestite nightclubs and sex shows that will make you feel like you're back in "Cabaret." Or, although it's a lot tamer now than it seemed in the '20s, the Cafe' Keese maintains the old Berlin tradition of allowing women to ask the men to dance to the waltz and foxtrot music the band plays.

If you're hung over the next day, don't worry; there are lots of places you can get breakfast until 4 in the afternoon.

Berlin is like a huge unfolding flower, always revealing new and interesting facets of itself. I've been there a dozen times since my college introduction, often for prolonged periods, yet the city never fails to surprise me. Berlin welcomes you warmly but slowly; it invites nudging and poking and exploring, a lifetime of discoveries.

Recently I've discovered "green Berlin," the city's 50 square miles of lakes, parks and forests, more than that of any other city in the world. Most visitors see the Tiergarten Park in the heart of town and the zoo, but the real glories of Berlin greenery lie on the outskirts of town, in the Grunewald Forest and the lakes it surrounds. Here in the west, the Havel and the Spree, the two rivers in whose valley Berlin nestles, merge and spill into numerous lakes amid a riot of sylvan scenery, and you can completely forget you're in a city at all.

A friend of mine lives on the edge of the forest. One sunny Sunday afternoon last fall, we set off on a tramp through the woods to a small lake on the Havel River not too far away. It turned out to be a very typically German thing to do; we ran into whole families of hikers -- also joggers and horseback riders -- along the well-trodden paths.

In a clearing along the way, we came to the Teufelsberg (Devil's Mountain), an artificial hill created from the rubble left of Berlin after World War II. We climbed to the top (actually, in German fashion, there are some nice wooden steps that take you very neatly to the summit) and watched young Berliners fly their kites above a wide-spreading view of the city, East and West. In the winter, the hill is a popular skiing area. At 377 feet, it's the highest hill in this otherwise flat city.

At the Havel, we stopped for a drink at the Wirtshaus Schildhorn, another trendy new establishment set up in a former boathouse. Its glassed-in sun porch area provided a relaxing panorama of the lake, gleaming silver against the dark green of the surrounding trees and studded with sailboats skittering in all directions.

In the summer, a number of beaches are open for public bathing, and a peculiarly Berlin twist on the usual Germanic order prevails: There's a beach for families, one for nude bathers, and one exclusively for dogs.

If you're not swimming or sunbathing, though, one of the most pleasant ways to spend a day in Berlin in fine weather is to take a boat cruise down the city's miles of canals and rivers, from the Tiergarten downtown out to the Wannsee.

Or take a stroll through Glienicke Park, one of the most beautiful landscaped parks in the world, designed to echo the poet Goethe's famed journey to Italy through the Alps. A ferry will take you to Peacock Island in the middle of the Havel River; yes, real peacocks freely roam its splendid, tree-laden grounds.

At Glienicke, you'll also come upon the renowned Glienicke Bridge, divided, halfway across its span, by the line that separates East from West, and the scene since the Cold War -- and very recently -- of noted spy and prisoner exchanges. Across the bridge, ironically dubbed the "Bridge of Unity" by the East Germans, is Potsdam, now part of East Germany. All the water around the bridge is, like it, divided in two by an invisible line as impassable as a wall.

It's easy enough, for a good deal of the time, to forget about the Wall in today's West Berlin, since the atmosphere of freedom, well-being and stability is too strong. The West Berliners have grown quite blase' about the Wall, accepted it as a part of the landscape and incorporated it into the same.

Most of its 100-mile-stretch is covered, on the western side, with graffiti and mural-like drawings, not all of which carry a political message. More recently, it's been used as a backdrop for rock concerts and other outdoor festivities. In its tourism drives, West Berlin tends to downplay the Wall these days; it's usually only third or fourth on lists of sights to see.

A large percentage of West Berlin's current population was born since the Wall went up in 1961, and for these young people, it's just something that's always been there. Many of them, in fact, admit quite candidly that they never think about the Wall and have never been over to East Berlin. When the Wall turned 25 last August, organizers failed dismally in an attempt to stage a hands-along-the-wall-style demonstration.

But every day, the tour buses still pull up to the observation platforms near the old Reichstag in West Berlin. Visitors climb up and down the skeletal steps, snapping pictures and exclaiming over the differences between the comfortable glitter around them and the drabness they see in the East, beyond the Wall.

A visit to Berlin is not complete, and not real, without a look at the Wall and, just as vitally, a trip to the other side. It's not just that you have to see the contrast to grasp the real value of what West Berlin has achieved and has to offer. It's also that East Berlin, for all its differences, is still half of the same city, and an important half, encompassing all of the former historic city center of Berlin.

You can't get a sense of what the city really must have been like in its heyday without seeing East Berlin. And besides, in its backwardness, East Berlin has retained much of the atmosphere of prewar Germany and exists, in many areas, almost as a living museum.

"We have to go over to see what Germany was like before the war," an enthusiastic American mother admonished her reluctant daughter one day last fall as I was waiting in line to cross over Checkpoint Charlie, and she was right.

I've probably crossed over Checkpoint Charlie or the Friedrichstrasse S-Bahn station to East Berlin close to 50 times, and the experience has lost the ominous quality it held for me the first time I made the trip alone. But passing through the kennel-like passageways, locked at either end, that control pedestrian traffic through the crossing point is always enough to make me appreciate western freedom of movement.

A day visa to East Berlin, which allows you to stay until midnight, costs 5 marks plus an exchange of 25 West German marks into 25 East German marks and is issued on the spot.

Once across, everybody notices the same immediate differences between East and West; the East is grayer, grimmer, seedier, darker. There aren't as many cars on the street or people on the sidewalks.

East Germany has worked hard to spruce up East Berlin's image for its own celebration of the 750th anniversary of the city, although it's also taking the opportunity to promote its claim to East Berlin as the capital of East Germany and as an autonomous city, separate and unrelated to West Berlin. The West is opposing this claim by including East Berlin festivities in its schedule of events and by urging western tourists to make the journey across the Wall.

Along the famous street of Unter den Linden, once Berlin's main promenade and the heart of the city, now waggishly described as "the prettiest dead-end street in the world," major historic buildings have received facelifts in preparation for the birthday bash. The grand neoclassical Staatsoper or State Opera House reopened to acclaim last fall after a three-year shutdown for exterior and interior renovations.

The historic buildings that line this street, from the State Library to the cathedral to the museum buildings on Museum Island, are among the finest you'll see anywhere in Berlin, although many are still grime-covered and dingy-looking from all the air pollution, and still bear scars from the war. At the end of Unter den Linden where it runs into the Wall, the Brandenburg Gate, symbol of Prussian triumphs past, is an especially poignant sight, still grand but adrift and neglected in its no-access zone.

Further along, at the Alexanderplatz, East Berlin's administrative center, the present takes over firmly in the guise of numerous buildings of the socialist realism shoe box style that plant you decisively in the Eastern Bloc.

Here is the Centrum department store, East Berlin's answer to KaDeWe. Its cavernous interior is a model depiction of the shortcomings of communist bloc economies -- small supplies of third-rate goods fill display cases, and clothing racks are arranged without any sense of esthetics or imagination.

On the other hand, the East Berliners have captured some sense of western panache in the Nikolaiviertel, a recently finished residential-commercial development around the rebuilt St. Nicholas Church, Berlin's oldest. Taking a stroll through this pseudo-renaissance village just a couple of blocks from the Alexanderplatz will remind you a little of Disneyland, a little of a suburban shopping mall.

The area was reconstructed on the basis of both old plans and architects' fantasies, with old fac ades standing next to new. Its cobblestoned streets, cozy cafe's and small-scale shops are a nice respite from the austere and dour air of the rest of East Berlin.

To get the real sense of East Berlin, the best thing to do is to get out of the city center and take the U-Bahn to one of the residential neighborhoods a little farther away. This is where the real mood of old Berlin prevails; here, the city is sad and ponderous, still drenched in old-style bourgeois respectability, slowly moldering away.

The streets are still made of stone; trams still clang down their middles, unimpeded by much automobile traffic; and like a ghost from the past, an occasional horse-drawn hay or coal wagon will pass by. The dark gray fac ades of the old apartment buildings are pockmarked from the war, and crumble away.

On Schoenhauser Allee, a commercial street in the working-class district of Prenzlauer Berg, the shops still display their 1930s de'cor, complete with old-style neon signs in lurid pink and green.

Signs of modernity, though, have crept into the back ways of East Berlin. Western-style discotheques and cafe's dot the commercial strips in most residential districts -- although their de'cor and ambience manage only to evoke, say, the late '60s at best. There's something a little sad about all these places, trying to shine brightly amid the gloom all around them, but they definitely offer a reprieve from drabness to the citizens of East Berlin.

A friend took me to the Cafe' Papillon, a privately run establishment that caters to the East's own well-off young trendies with money to burn. On a dark side street in Prenzlauer Berg, the place had an inconspicuous fac ade. But inside, it was crowded with couples and groups hunched around the miniature tables, sipping coffee or wine and talking in urgent murmurs, the hum punctuated by occasional laughter. Across the room, two transvestites, a novel sight in East Berlin, preened broadly and kept the assembled company well entertained.

Two East Berliners joined my friend and me for some wine and talked for a couple of hours about their lives, ending up with a morose discussion of their chances of ever leaving and what life must be like drueben ("over there").

"Over there," of course, is West Berlin, to which it is a distinct relief to return after a visit to the East. But I always like to make one final pilgrimage, back in West Berlin, to remind me of the things this city can teach you in a way no other place in the world can.

In the far southwest corner, past the Grunewald Forest and the big Wannsee Lake, is a tiny hamlet called Steinstu cken, no more than half-a-dozen houses sitting square in the middle of East Germany and connected to West Berlin by a single road. The road is lined on both sides by the Wall, and the houses of Steinstu cken are completely surrounded by it as well. In most, you look out the window directly onto its gray stone not more than three or four feet away.

The queerly claustrophobic atmosphere that reigns here is, to my mind, the final word on today's Berlin, as forward-looking, progressive and thrilling as it is. In Steinstu cken, Berlin, nobody ever forgets about the Wall. Zofia Smardz, former Bonn correspondent for Newsweek magazine, is a free-lance writer.