Old ruins. New ruins. Both are drawing cards in Lebanon these days. In fact, curiosity about the recent scenes of strife seems to entice as many visitors as historical interest in this small country's ample supply of Phoenician, Roman and medieval fortresses, temples and palaces.

Actually a visit today to Lebanon, even to its "war shattered" (a misnomer) capital, is enlightening and surprisingly rewarding. Things aren't as many people believe they are.

In some sections you cannot see evidence that anything happened during the bitter two-year "civil war." The shops are open, there's no lack of well - even fashionably - dressed people moving purposely along the streets. Fine restaurants still offer the cruisine of many nations, as well as their own delightful 30-dish

mezzes Lebanese version of the smorgasbord). Parking appears to be as much of a probelm here as elsewhere in the motorized world.

Yet a few blocks away there's complete devastation, involving perhaps a third of the old city. A solitary chimney or stairway attests to a building that once was there. Fronts or sides of other buildings are missing, leaving a gaping second-story floor sagging. The Holiday Inn sign is burned and lying on its side. Rubble fills former gardens and patios. And everywhere the Syrian army (about 30,000, it is said) patrols, with camouflaged tanks and guns flanking the main crossroads.

In spite of a six-month concerted effort by the Lebanese Tourist Board, there are not yet many North American visitors. But businessmen from the United States and Canada began streaming back this past summer, and they are busy negotiating with their Lebanese counterparts who are as anxious as the foreigners to get things back to normal "now that the nightmare is over."

When their work is finished, the businessmen join the throngs of European and middle Eastern tourists who jam the beach clubs along the esplanade. In fact, it's wall-to-wall people around the pools at the Saint Georges and Coral Beach Clubs. yachting and water-skiing enthusiasts are much in evidence.

But the big tour buses are missing at such major attractions as the Cedars of Lebanon, Byblos, Baalbeck (listed by many as one of the seven man-made wonders of the world) and Beit ed-Dine. Enterprising and hopeful guides are ther, though, and souvenir shops and cafes are operating. Venturesome types, who aren't deterred by often inaccurate accounts of the proximity of real fighting, are driving themselves to the principal tourist attractions - as well as into the lesser-known but equally interesting valley and hillside villages for a close-up of Lebanese life today. Some are hiring taxis with English-speaking guides (French and Arabic are the local tongues, but English is a close third) at about 30 per cent less than they would have had to pay five years ago.

These determined sightseers ars enjoying the more casual pace brought about by the lack of crowds at the Temple of bacchus and the Chateau des Croises in Byblos, the "world's oldest city" (7,000-plus years, but Jericho also claims the title), which gave its name to the Bible. They're relishing the opportunity to read inscriptions, including the first alphabet, at leisure, to savor each relic from the past without being pushed aside by the next in line.

The slight inconvenience of frequent stops at armu checkpoints, they feel, is a small price to pay. "Besides," said one servicemen's wife stationed in Europe, "I know it's deadly serious, not all honey and pistachio nuts, but have you noticed the checkpoints are frequently decked with greens or flowers?"

I arrived in Beirut alone at 10:30 p.m., after having taken off from Kennedy on Alia (Royal Jordanian Airline) at midnight. We had landed in Amman in the early afternoon. With changes of planes, red tape and a few ground delays, I was finally ready for a darkened Beirut and the friend of a friend who was supposed to meet me, but didn't (He'd expected me on Air France.)

Smiles and gestures, plus the printed name of my hotel, got me into a taxi with a non-English-speaking driver. At the airport exit we went through the first check. The driver switched on a makeshift light that shone into the back seat. The soldier peered at me, and my passport, then said something to the driver, who translated. "Speak Arabic?" he asked. I shook my head "no" We were waved on. This happened four times before we reached the hotel. Fortunately my reservation there was in order.

The next 10 days were filled with check-point stops. Sometimes the pair of soldiers merely waved us on, bored with the operation. At others, the car was searched and pur papers (including the guide's and the driver's) were gone over minutely, although I often suspected the soldier could not read. Once our driver thought he'd been waved on. The guard thought otherwise. We were stopped and held a scary 20 minutes before being allowed to proceed. Another time two guards stopped us, looked us over carefully, spoke to the driver in Arabic, and climbed in. "Hitchhikers," and my guide.

But aside from the destruction of the one-time "hotel strip," where 1,500 of the total 9,000 pre-war hotel rooms were lost during the days of heavy violence - they are soon to be replaced - and the fact that when I inquired about going to Tyre I was told, "It's not advisable at this time," there was little to interfere with my enjoyment of Beirut or Lebanon as a different type of tourist destination.

Life here appears normal. Banks are operating, the Stock Exchange (the only one in the Middle East) reopened in September, but the Archeological Museum is closed. It was struck by 30 shells during the war, and won't be reopened "until the situation is fully stablized."

Meanwhile, the director of antiquities, Emir Maurice Chehab, is holding a priceless collection of early Phoenician and Egyptian jewelry in a secret and safe place. He's also checking into the foundations and sub-layers of the heavily shelled downtown areas, which have already disclosed many archeological treasures. "Enough," says Chehab, "to warrant setting up special digs to precede the establishment of a major city park in this section."

Plans for rebuilding the city are already well beyond the talking and drawing board stages. "Financing has been arranged, $2.3 billion in fact," explains Percy Dehan, who heads the Lebanese Tourist Board in New York City. "Through the World Bank, with a British and French team of architects. Work is expected to start soon." Already the arrival and departure lownges of the airport have been rebuilt and 24 of the 36 airlines that served Beirut before the war are now operating. Air traffic is climbing steadily.

The staff of the American Embassy, which dropped to 60 during the war> is back up to 150, and an American firm that formely had 225 employees now numbers 175 on its payroll. "Why not?" asks the American manager.Beirut has the best telecommunications in the Arab world, and with the American University School now operating normally, this is a good spot for foreign service.

I stayed at the Vendome, a luxury hotel with a French flavor overlooking the sea. Highly polished woodwork. Crystal chandeliers. Gourmet restaurant. Oldtime European service. There wasn't a scratch, a bullet hole or a brick out of place. (The story goes that a little money changed across the street, once a craft center, was left a shattered shell.) The Vendome is now one of the Intercontinental family and regularly entertains Middle East VIPS. A large group of these, in flowing white robes and with heavily armed guards, were fellow guests during my stay.

Americans are definitely "in" in Lebanon. The people are well attuned to Western culture. T-shirts with Donald Duck, and Snoopy ballons, as well as those sporting more modern catch phrases, are everywhere. Shops are named Buster Brown (textiles) and Happy Baby (kiddie toys.) in Mohammed Houssan's brass shop> plates bore likenesses of Andrew Jackson, Lincoln and Hamilton, as well as the American eagle. They were designed originally on order for a woman in Prattville, Ala., but Houssan was intrigued and made duplicates for the American tourists he hoped soon will be returning.He and his family have been operating the brass shop for 600 years, and his son, Hassam, about 8, was already following in papa's footsteps.

In a field beside the road we followed through this fertile grape and grain belt of central Lebanon, we saw a goatherd wearing a yellow construction hard hat, while in the souks the older women were wearing black half-veils so old the black had turned green.

Lebanese handicrafts are on the way back through efforts by the Committee of Lebanese Handcrafts, which was set up with the help of more than 200 craftsmen. The old arts of jewelry making, weaving, embroidery, carving and leatherwork are being revived, and displays have been placed in hotels and at the Tourist Office Beirut.

Nasser Safieddine, director of the national Tourism Council's overseas office, noted that price increases due to inflation have been offset by a favorable (for Americans) drop in the exchange value of the Lebanese pound. This year will see the opening of Summerland, a giant hotel-shopping-entertainment conglomerate by the sea in the Northern Beirut suburbs. Meanwhile, the Casino is open and popular with both local people and visitors, to the point where my drover had difficulty finding a place to park. The show, though, was more folkloric than the former international fare, and the dinner only mediocre.

For further information write the Lebanese Tourist Office, 405 Park Avenue, New York 10022.