The Monster dwells in an alley somewhere in Northwest Washington. I can be more specific than that: I am sworn to secrecy.

The Monster - 11 feet high at its peak, with a remp sloping sharply to the ground from just below its midsection - is built of some two-by-fours, a four-by-six, assorted other lumber and "a lot of nails," according to is designers.

The Monster has a peculiar diet: "It eats skateboards," says Rick Knauth, 14, one of its four creators. (The others - Tom Fitzgerald and Danny Hawke, both 14 also, and Mark Sullivan, 16 - share Knauth's fear that divulging The Monster's specifc location would attract crowds.)

Sometimes The Monster eats the riders, too, who skateboard down the ally, up the ramp and soar as close to its peak as they can before clacking to a rough descent.

Often the skateboards fly out from under the riders and crash to the alley's asphalt. Sometimes the riders follow. And The Monster just grins its evil, orange, gap-toothed grin, painted on for posterity.

At the base of the ramp is the warning "Ride at your own risk." But about a dozen youngsters, most between the ages of 12 and 16, have challenged The Monster almost daily since building it in the early summer.

"We've just used it for days and days on end," says Knauth. What's their goal?

"to reach the top," said Knauth.

Sullivan, who has signed and dated (Oct. 7) the 10-foot mark on The Monster signifying the highest point anyone has reached to date, says, "I want to scrape my rear axie on the tip of The Menster."

Most any afternoon after school the alley echoes with the clackety-clack of speeding skateboards as riders attack The Monster with an assortment of tricks, flips and turns. Several begin with a "rideoff", which involves holding onto a piece of cord attached to the board, skating up the ramp and then sailing off the side into the air. In theory, pulling on the cord should keep the board flush against the rider's feet. In actuality, board and rider often fly in opposite directions, landing on the alley floor.

"That's how you get 'road rash," says Alex Gonze, 12, pointing to an elbow studded with scar tissue.

"But we haven't had a single serious injury," interjects Knauth, aware of the concerns of adults since most riders' parents have examined The Monster at least once. "Yeah, my mom was a little worried about me at first, but not anymore."

Knauth and the others take safety precautions such as waiting for the ramp to be clear of riders before starting their ride to ward. The Monster. They discourage excessive horseplay.

"One guy pushed his baby brother up the ramp in his Big Wheel," Knauth recalls disapprovingly. "The thing came flying down - wrecked the Big Wheel, but the kid was okay." Some riders wear elbow pads or gloves to ward off road rash, but most expose their limbs to the perils of The Monster. Words of encouragements and admiration are muttered as the riders perform.

Knauth watches a blond newcomer known only as Adam, from California, the Skateboarding Capital of the World, zip up the ramp, spin around one and a half times on his board within a flinch, and make a perfect, graceful descent. "Now that was nice," Knauth says softly.

Joe Richman, 12 rides up the ramp, jumps and turns in the air, landing on his board for the ride back down. "A nice piroulette, "Knauth says.

"I'm going for it!" someone shouts, and the cry "Look out, he's going for it" is picked up in the alley. In means that someone is going to try skating to The Monster's peak. Everyone watches, not wanting to miss what may be the history-making ride to the top.

The riders say getting up the ramp to six or seven feet isn't that difficult. But getting back down in style involves executing a "kick turn" - turning around by stepping down hard on the rear of the board, which spins the nose around.

"It's a great feeling when you're going up there," Knauth says. "You feel weightless. The longer you can prolong before you kick turn, the longer you feel weightless."

Still other riders work on "fakies", where they ride up The Monster without turning and desce d backward. "See, they don't really do anthing - they fake it," explains Knauth. "It feels like a roller coaster ride."

Being skateboard crazed is all-consuming. Riders spend $70 to $100 on their boards, and many own more than one. Some make their own. And all refer to Skateboarder Magazine as the "Bible".

"If it says to eat wheels," says Danny Hawke, pretending to chomp on his board, "then we will".

"There are a lot of second-rate magazines around about skateboarding", says Knauth , "but they're garbage. They have pictures of Baretta or Farrah Fawcett riding, but we're not impressed by that. They can't do anything that we can't do."

hough conquering The Monster is their immediate goal, the hard-core skateboarders have wider fantasies.

I'd like to do more 360s (spinning rapidly in complete circles while standing on the skateboard) than anyone," says one rider, adding that the unofficial world record for 360s is currently 78.

I've heard of guys who ride through a pipe that drops them about four feet into a bowl," says another, starry-eyed. "I'd like to try that." Still another talks of riding with his feet strapped to his skateboard.

But for now The Monster has captured their imaginations.

"We're gonna completely overhaul it this winter", says Hawke. "We're gonna put on metal corner braces and a new, terpered wood surface."

"Yeah, says, Knauth, "And we want to put a Plexiglas window in the middle of it so we can which people go up from behind The Monster."

Knauth pauses to watch a friend "go for it." He doesn't make it to the top, but executes a sharp kick turn.

Knauth's eyes light up. "Just think. With that window in, we could get some really hot pictures of moves like that."