Wacky, that's what it was. Well, because Bob Cassilly actually had a check for $250,000 in his hand when he showed up last Friday, uninvited, at the mayor's office, maybe what the sculptor/entrepreneur was doing was eccentric.

Beachfront property on Oakland Avenue. An indoor roller coaster. A giant public building with no air-conditioning, surrounded by a facade resembling a Roman aqueduct. Fountains, 100-foot concrete whales. And around it, behind the facade, some 400,000 square feet of commercial space. Sounds like a plan to Bob Cassilly.

But City Hall didn't take Cassilly's nonrefundable, contingency-free earnest money he wanted to give them to save the Arena. The response from Mayor Clarence Harmon was thanks, but no thanks, with the unspoken question being "Where have you been for the last five years?"

The Arena is set to be blown up in February after sitting empty since 1994. Cassilly, who is a sculptor, real-estate mogul and creator of the City Museum downtown, says he made his initial pitch now because he had just read the details of the proposed deal the city plans to make with Balke Properties to put an office building where the Arena now stands.

"I was shocked," Cassilly says of the terms of the deal. "I'm a professional bottom-fisher. I know a deal when I see one."

So when he and his family took time off at the end of the year in Cabo San Lucas on the Baja Peninsula in Mexico, Cassilly took his clay and modeling tools along to help him visualize what the Arena could look like with a little imagination -- and a few million bucks. He came to the conclusion that it could be saved.

"They're tearing down the Arena for no good reason whatsoever," he says. "They have no tenant; no prospect of a tenant; they don't have a deal with the developer; the developer has committed nothing; the city is forced to spend $700,000 on tenant improvement before the developer signs on the line," says Cassilly. "But it's not too late. It has wonderful drama. It's not the 11th hour, it's the 12th hour."

Cassilly's bravura entrance to Room 200 of City Hall on Friday followed an unscheduled private audience the preceding week with Mayor Harmon after Harmon praised Cassilly at the City Museum in an address to Realtors. Cassilly diverted Harmon into the kitchen, where Cassilly stores his clay model of what he hopes the Arena will look like if he gets his hands on it.

"I ambushed him," says Cassilly. "I said, 'Mayor, I'm so glad to see you. Thank you for saying all that stuff about me. Let me show you my plan.' He very patiently stood there for 15 minutes and humored me. Then he said, 'Fifty thousand a month -- what about that?' And I said, 'If the $50,000 a month was taken care of, would you stop Spirtas?' And he looked me in the eye and said, 'Yes.'"

Well, so much for what's discussed in a kitchen. The $50,000 that Harmon referred to is the monthly payment on the $6 million loan the city took to buy the Arena in 1986. Kiel Center Partners then built Kiel Center downtown with a $35 million city subsidy, with the stipulation that the Arena be eliminated as competition -- that it not be used for any spectator event requiring an admission fee. Spirtas is the company the city has hired to demolish the Arena for $694,000.

In early January, the nonprofit Gateway Foundation told the mayor's office it would cover the $50,000 monthly payment for 12 months in order to buy time until a way to save the Arena could be found. Cassilly says the $250,000 check he took to City Hall is earnest money toward the eventual purchase of the Arena property on Oakland.

Under Cassilly's offer, a $1 million federal "brownfield" grant would pay to have the asbestos, lead paint and other hazardous materials removed from the building. Because his plan could be seen as an improvement of sorts to Forest Park, across Highway 40, he would anticipate the $3 million pledged by the Art Museum to help develop the property. He would pay the city $1.5 million within a year for 20 percent of the property and eventually could pay as much as $9 million over five years, which are terms comparable to the deal the city is negotiating with Balke Properties.

The major difference for the city, financially speaking, is the upfront money: Cassilly is putting up more than Balke's $50,000.

But the difference between Balke's plan and what the impresario of the City Museum wants to do is more than financial. By saving the Arena structure and converting it into a public space that might include an ice-skating rink, an indoor roller coaster, art-exhibition space and who knows what else, Cassilly proposes to make a philosophical statement -- though he is quick to add that there would be significant commercial development around the gussied-up Arena.

"Right now, what have we got here?" Cassilly asks. "A building with a replacement value of $100 million and a huge parking lot. You tear down this building, and you've got an ugly old parking lot and you're on the same playing field as the county, except that you're in the city. You're giving away your one possible advantage. Every shopping center, every development is looking for an icon, a 'big kahuna.' These things exist because of the centerpiece. There's a symbiotic relationship going on between the nonprofit public place and 80 percent of the space that's for-profit, that gives the city earnings tax."

In less conceptual terms, Cassilly means that by providing a beachlike, sand-filled playground fronting Oakland and decorating it with giant whale sculptures and fountains and turning the Arena into some public building with an amusement edge, you offer something that Chesterfield or Maryland Heights doesn't. So the city could save the Arena, though with a radical facelift (see photo) and still attract commercial office-space development around it.

That would be competing with what Cassilly calls the "suburbanization" of life without surrendering to it: The city shouldn't mimic what happens on its fringes.

"How much lower can you go? They're doing it for no good reason," Cassilly says of the demolition for an office park. "Their highest accomplishment would be to come up with a banality which exists everywhere else. That's the goal. It's like a Third World country wanting to be like America -- so they adopt the worst traits of America.

"It hasn't worked anywhere in the city of St. Louis. Imagine one public thing that's worked in the city. They wanted a suburban shopping mall downtown, and they tear down the retail stores and build St. Louis Centre. Then they try the low-end stuff at St. Louis Marketplace."

Cassilly is not just an artist prone to idle brainstorming. In addition to being the prime mover behind the eclectic City Museum, he has done a bit of real-estate wheeling and dealing. He claims to have owned 45 pieces of property at one time or other and that "on average, my properties are worth 20 times what I paid for them." In 1993, Bob and his wife, Gail Cassilly, bought two 10-story International Shoe Co. buildings for $525,000. He estimates that the two renovated buildings, which include the City Museum, are now worth around $10 million.

"The value went up. This is a better-valued property afterward than before," says Cassilly, referring to what is now called the International Arts Complex. "The opposite is true of the city. What have they brought us? St. Louis Centre; the place out on Manchester -- the St. Louis Marketplace; the top of the old Union Market that's a Drury Inn now. Everything they touch turns to shit. These people are pissing away history and a good deal for nothing. There's no compelling reason to do that. It borders on incompetence.

"I've got as much or more credibility than Balke," Cassilly says. "I've lived in the city; I've been successful in the city; I've never lost any money on any real-estate transaction I've ever made."

To come up with the earnest money he offered the city, Cassilly says he used the "unconscionable profit" he gained from the sale of one of his properties downtown.

The deal the city has on the table with Balke worries Cassilly, because he sees the possibility of the city paying for the demolition of the Arena, then Balke only buying 20 percent of the land -- the part that fronts Oakland -- then declining to buy the rest. "They could make the rest of it useless by just using the strip in the front and then say, 'Sorry, city, the rest of it doesn't have any value," Cassilly says.

Balke's first tenant was going to be Safeco Insurance, which had considered moving its regional headquarters from Sunset Hills to the site on Oakland Avenue. Safeco decided against the move, and no new tenant has stepped forward.

With Cassilly's idea, the tenants would come because of the interaction of public and private space, as well as the spectacle the Arena would become. The new roof would be copper, weathered to a "green patina," Cassilly says. A giant "fanciful creature" would be sculpted on the top of the roof. All the "baby-playpen-yellow paint" would be covered over and all the advertisements banished.

In a way, it would be a different version of the same theme that worked at Union Station, though it would not be a shopping mall or a retail-arcade approach. Ironically, Balke was involved in developing Union Station. Cassilly isn't very concerned at this point about what exactly would be going on inside the building, though he says he has 10-15 ideas.

"Doesn't make any difference," says Cassilly. "Right now it's an ugly dog. You turn it into a jewel. It could have the same relationship that Union Station has to the outside perimeter developments. Ironically, what Balke has done in Union Station is only possible because Union Station is there."

In other words, if Union Station had been torn down, any boutiques or shops behind it would not have thrived. Both the Arena and Union Station, in this comparison, are architecturally significant structures on major thoroughfares. Saving the old in this case, Cassilly feels, is saving something better.

"Remember when you were 8 or 10 years old and you're going into the Arena for the circus? It's huge and dark and threatening, huge halls with chewing gum on the floor, and shiny lead paint all over the walls, and arches upon arches, just like Rome. You go there early and you see the animals, the tigers, the lions. You go up in the stands and it's forever, it's huge, it's awesome, it's full of cigarette smoke and light. It's dark, threatening. It's unlike any suburban experience. It sticks with me to this day," says Cassilly.

"If I were to go down as a child to the Kiel Center, it looks like the world headquarters for Baskin-Robbins motivational courses. It doesn't have it. It's got no personality."

Having made his personal pitch to the mayor, concocted his clay model and waved his $250,000 check around in City Hall, Cassilly is not unaware of the odds.

"I'm trying to think of this like a snowball, although a snowball's chance in hell might be more accurate," he says. "You see me out there on a bulldozer, out there building big fish and making mounds. They say 200,000 cars go by there a day; they might see this and say, 'Hey, I think that's a good idea.' I'd have this place such a show by springtime. People would be going by seeing that Don Quixote is out there beating the windmills."

And in the end, Cassilly believes it would sell. "It would be interesting enough and different enough. If you want something in real estate, you have to offer something that no one else will offer." Getting rid of a funky relic like the Arena, he says, would be "tearing down the only thing the city has."

But Cassilly realizes that the only event that is delaying its demise is the papal visit; the lot is needed for parking. The city just isn't interested in taking what it considers to be a gamble on prime real estate. And Cassilly's timing is bad, he realizes.

"I have no objection with the reasonableness at this late hour of saying no. I can't intellectually say that's wrong. But emotionally, nobody wants this thing to happen, and it's being done by people who have a proven failure record," says Cassilly. "They'll look back in 10 years and say, 'How could they have done that

?'