In my scenario, it starts with a 4-year-old finger pointng at a picture in my picture book. "Horsie," says the voice that goes with the finger. You look. You frown. Your child is, well, uninformed. It's not a horse, it's a camel. You ponder. How to light up this dim bulb? Then revelation comes. It's time for a trip to San Diego.

Obviously, there are zoos closer to New York, Wisconsin, Colorado, Connecticut and Oklahoma where you can point to the proper creature and say, "See, that's a camel." Why, then, on June 2, where cars with there license plates among the hundred in this Southern California city Balboa Park?

I submit it was because when a loving parent thinks "zoo," the next thought is "best zoo" and that moves you directly to San Diego.

True, that doesn't exactly explain the three white-haired senior citizens who were in the admissions line just ahead of me, the chic blond European women in a black jumpsuit, the professional-looking make wearing a suit and tie, the five punk rockers or for that matter, me.

None of us had the excuse of children. We were there anyhow. Let me therefore speculate again: I do believe some of us turned up because we know a good thing when we hear about it, and right now both San Diego and its eye-popper of a zoo (3,200 animals, 765 species) certainly qualify as two of them.

If you haven't been there lately, San Diego will pop your eyes, too. For one thing, its waterfront has added a $14 million collection of ships, restaurants, outdoor cafes and Coney Island's Grand Old Broadway Flying Horses Carousel. Seaport Village and adjacent Embarcadero Park opened in mid-June last year on the site of the old Coronado ferry landing and appears to be doing just fine. Given panoramic views of sailboats, high-powered tuna fishing boats, king-sized Navy ships and the like, they're hardly likely to do otherwise.

An Aerospace Historical Center opened last fall in Balboa Park to replace a smaller one that burned down three years ago, and to get to all these places and more, there's now a Bus That Goes in Circles. The bus now completes a full swing every two hours and 15 minutes between 8:17 a.m. and 6:08 p.m. and travels between the beaches, San Diego's Old Town complex, the famous Sea World show, hotels, shopping malls, Balboa's Park's museums and zoo, the sports-fishing landing, and other attractions. There's also a new trolley starting July 19 that will take passengers on a 16-mile fun between the city center and the Mexican border, or just on 25-cent trips around downtown.

In short, San Diego looks a lot like a city that's been through a Charles Atlas course. Consider that less than 100 years ago it was a puny little thing bristling with cactus and so arid that at one point travelers were advised to bring their own drinking water. Today it's a lucious blue-and-green playground that qualifies as one of the country's major resort cities.

I'd vote for it for three reasons:

No. 1 is that it's hard to beat the climate. If you don't like what they have, say, downtown, you can drive 30 or 40 minutes and sample something else, with mountains, desert or seacoast for surroundings.

No. 2 is that same variety of surroundings, with the added attraction of Mexico so close at hand.

No. 3? Well, for the moment the price is right -- or at least about the closest thing you'll get genuinely affordable for families, low-budget trvelers and people who want style but also sanity in the price tags attached to it.

The top-class hotels do play sock-it-to-you, but there seems to be some recognition that this sort of thing can kill mass travel if it goes too far, so it generally stops shorter than at comparable places elsewhere. The Vacation Village Hotel (where lately Ryan O'Neal has been making a film) has summer rates, single or double, of $62 to $88, but the are $74 and if you're a tennis player it pays to ask about package rates.

Kona Inn, which has all the beach and sports extras you can think of, has double rates of $52-$54, or $44 if you say you've seen the rate in L.A. magazine. The popular Catamaran (pool, beach, marina with rental boats, Jacuzzi and $6.50 chuckwagon dinners) is $44-$80, after July 19 $50-$90. Even the grand old Gingerbread Palace, where Marilyn Monroe, Jack Lemmon and Tony Curtis filmed "Some Like It Hot," the beachfront Hotel del Coronado, has a few twin-bedded street view rooms for $65 although you have to work far ahead to get them. (Otherwise, you'll pay up to $158 for a double room in the old building, $143 in the new building.)

From a penny-watcher's point of view, one of the biggest magnets could be the number of attrative restaruants where $15 can still buy dinner for two. For the record, let it also be said that you don't have to look to far to find breakfast for under $2, drinks for $1 and lunch for under $4; some museums have free admission days (usually Tuesday or Wednesday); the San Diego tourist information offices give away lots of literature with discount coupons; there's a Motel 6 ($ 12.95-a-night single) and several other budget spots tucked right in the central tourist lodging area rather than somewhere in the boonies.

In addition, a sizable number of food and transportation discounts exist for senior citizens; there's free parking at Balboa Park, Old Town, Seaport Village and most other sightseeing areas; name-brand car rentals go as low as $119 a week with unlimited milage; the U.S. Navy welcomes you with lost of free sightseeing opportunities; many of the beaches -- II public -- are equipped with free shower and toilet facilities.

In fact, in the money department perhaps all you have to beware of are the taxis. They've been "deregulated," so companies have different price structures. This has led to confrontations and shouting matches at the airport in particular, when for reason of price, passengers don't want to use the cab at the head of the line. Well, as they say in their tourist ads, "San Diego Is America's Wildest City."

Of course, that tag is supposed to be a reference to the zoo and its 9-year-old offshoot, the Wild Animal Park, and it's apt. Between the two spots, they have just about everything except giant pandas and white tigers.

But even without their koalas and other unique attractions, their layouts would make them winners. The landscaping is appropriately jungle-like, and birds and animals are kept in minimal enclosures. That means that at the Wild Animal Park, located about 30 miles from downtown but still within the city limits, you travel the territory by monorail ($7.25 for adults, $5 for children). Or, if you've made the required advance arrangements through the Visitor Service Office at (714) 747-8702, you can take a remarkable $35-$50 tour in an open-top Photo Caravan truck, into which the zebras and other animals frequently stick their heads.

At the zoo you can ride an overhead Skyfari, are a guided bus tour, visit baby animals in a nuresery that's part of the Children's Zoo, or for just the normal $4.25 admission ($1 for children 3-15), walk around all day, talk to any animals you want to and watch the free sea lion show.

I watched my own free sea lion show by moonlight, though, while having a late-evening dinner at the oceanside Marine Room Restaurant in suburban La Jolla. Actually I was sitting beside a window enjoying a shrimp cocktail when I realized a swa lion was having a free show watching me. A pup had come onto the beach and was matter-of-factly looking all of us over. That's San Diego: not only wild days, wild nights.