Above the karate dojo, below the cactus preserve and grape arbor, next to the in-house delicatessen, beneath the geodesic dome illuminated by soft neon, the waterfalls, the man-made rock mountain and cave, the rooftop grotto bar with the French desert ambience, behind the 1890s-style frontier dance hall facade, surrounded by the Dali-esque wall murals, under the ecological/theatrical library, the experimental film studio and the three residential apartments--well, now you've come to the very heart of the place.

That would be the theater itself, where a typical evening's fare might feature the works of Buckminster Fuller brought to life by an avant-garde repertory troupe known as the Theater of All Possibilities.

Yes, we are in Cowtown, U.S.A. Yes, everything described above sits under (or over) a single roof. Yes it's all quite batty to conventional aesthetic sensibilities. And yes, that's precisely the point.

It's the Caravan of Dreams, a $5.5 million avant-garde performing arts center/jazz club/cactus preserve/martial arts studio/etc. that, to belabor the obvious, is the only facility of its kind anywhere.

It opens Friday, smack in the middle of a handsomely face-lifted downtown that doesn't quite know what to make of its new neighbor.

The Caravan was dreamed up by Edward Bass, 38, the slightly eccentric scion of an oil-rich billionaire family that owns giant chunks of Fort Worth, and his eclectic band of artist friends and business partners.

"I view this an an opportunity to give back a lot of things that Texas gave me," said Bass, a Yale-trained architect whose exotic taste in entrepreneurship already has led him to develop a hotel-cultural center-library in Katmandu, a cattle ranch on the Australian outback and an experimental farm in the south of France.

For official consumption, the business and political establishment here is delighted to have the most far-flung of the Bass brothers return to lavish his home town with such an unusual treasure.

But unoffically, there's a bit of head-scratching going on. This, after all, is the most Texas-like big city in Texas. From the days when Wyatt Earp, Doc Holliday, Butch Cassidy and the Sundance Kid used to cavort here, it's always taken a rugged approach to the lively arts. Today, for example, Fort Worth boasts the the world's biggest country-western nightclub and honky-tonk emporium, Billy Bob's Texas, where, if you tire of the music, you can always watch a live rodeo.

"I think the word folly perhaps applies to this project," said one prominent businessman, who asked not to be identified. "It is a very unusual fruitcake of ideas of one very cultured but somewhat abstract man. And it's going to hit an insular town like a bolt out of the blue--sort of like rolling an F16 into the middle of an aborigine village. The natives simply aren't going to know what to make of it . . . .

"Eddie expects to have people sitting around reading library books, playing chess and contemplating the ecological balance of the universe," the skeptic continued. "Maybe that happens at Elaine's or along the Rive Gauche, but not in Fort Worth."

But Bass and his friends say they believe the setting is perfect.

"Fort Worth is so, as the French would say, typique," marvels John Allen, a Harvard-educated artist and management consultant who is one of Bass' six partners in Decisions Team Ltd., the decade-old company that is developing the Caravan. "It's full of vulgarity in the old root sense of the word, meaning people vitality. There's no phoniness here."

Allen says he believes that the avant garde arts can and should have broad popular appeal.

"We decided to fling this thing right down in the middle of the marketplace to see if we were right. We're going over the heads of the art establishment right to the people, and we're happy to accept the discipline of the marketplace. It drives phoniness out."

The doubters are legion.

"This is an extremely conservative, commercially oriented town when it comes to theater," says Jerry Russell, head of a local repertory group, who notes he has "a terrible time selling tickets" whenever he stages anything more adventuresome that "The Importance of Being Earnest."

Among the early bookings at the Caravan are Ornette Coleman, a Fort Worth native whose jazz disavows harmony, William Burroughs, the beat generation man of letters, Shirley Clark, a filmmaker whose documentaries shun narrative, and the Too Much Brothers, magicians from Morocco and Transylvania.

Just where the cactus preserve et al. fits into this lineup gets a bit complicated and conceptual.

"The karate dojo is for the man of action," says Allen. "The bar and restaurant are for the self-reliant man. The theater is for the man with vision and aspiration. The rooftop desert is for contemplative man."

He continues: "The big decision today, as we see it, is the ecological-cultural interface." And a bit later: "The main problem today is alienation. People need impression food--color, activity, drama. To put it in plain English, people are bored stiff."

If it still doesn't seem plain, other avenues of explanation beckon. The Caravan's chef is a Tokyo native who happens to be a fifth-degree black belt in karate. His dream has always been to teach karate by day and cook by night. At the Caravan, dreams come true.

Honey Hoffman, a DTL partner and head of the Theater of All Possibilities, a repertory troupe that started in San Francisco during the ferment of the late 1960s and later migrated to Europe, has never been enamored of the starving-artist life style. She's always dreamed of having her own, well-equipped theater.

At the Caravan, the cast bathrooms have hand-painted tiles. The stage of the 212-seat theater is outfitted with a special sprung-floor (it's easy on the knees) and there's a steel crane that rolls along the length of the ceiling for use in special staging effects.

"If they wanted to lift a 5,000-pound Peter Pan all the way up to the projection room, they could do it," mused one amazed architect.

Hoffman has also always loved jazz--"I like the way the musicians relate to each other on stage. I love the democracy of it"--and that helps explain the separate 350-seat jazz and blues nightclub.

Bass, meanwhile, has been looking for a place to live in Fort Worth, so that accounts for the apartments. (If there was just one, he wouldn't have any neighbors.) His interest in cacti stems from his early years as an architect in New Mexico.

The rooftop preserve will have 300 different species of cactus from four deserts--Sonora, Tehuacan, Namibia and Malagasy. "The desert is where the avant-garde has always gone for inspiration," says Allen.

The waterfall on the roof is there in part to drown out the sound of street traffic.

"White noise overcoming black noise, to use the jargon," says Allen. There are no special plans for the cave, yet. "We didn't want to design this to rigid specifications," he says. "We wanted to leave some room for artists of the future. A big part of avant garde has always been happenings."

The dreamers of DTL also see the Caravan as a way to bring people into downtown at night and as a mediating force among races and classes. They hope their low-priced breakfasts and lunches will attract a mix of hard hats, technocrats, blacks and whites.

On top of all this, they tout the Caravan as a commercial venture, expected to pay for itself. But they are vague on the details.

If it were mere whimsy, dream-fulfillment and philanthropy, certainly Bass could afford it. He is one of four brothers of a family reported by Fortune magazine to be worth $2 billion in oil, real estate and securities holdings.

The Bass family has long been considered a benevolent and civic-spirited force here. Edward's older brother, Sid, has just completed a $250 million renovation of the north end of downtown that features a luxury hotel, two skyscrapers and an upscale urban shopping mall. They've all been slow getting filled up.

The Basses are also patrons of more conventional arts, and their largess has helped build a fine symphony and some excellent museums here. Perhaps out of civic jealousy, other oil-rich Texans in Dallas and Houston are in the middle of massive fund-raising drives to beef up their cities' cultural offerings.

As far as the Caravan is concerned, that's all to the good.

"We're not on an anti-establishment trip," says Allen. "After all, to have an advance guard, you first need to have an army." CAPTION: Pictures 1 and 2, Geodesic dome and desert with bar top the $5.5 million brainchild of entrepreneur Bass. It also features entertainments from karate to avant garde theater. "I view this as an opportunity to give back a lot of things that Texas gave me," says Bass. By AP