A flier circulating at Acalanes High School identified the party spot only as "The Shack."
It didn't describe the 30-by-15-foot wooden structure illegally built in a secluded canyon in Briones Regional Park.
It didn't say the shack, apparently built by Acalanes students, had such amenities as a bar, couches and a fire pit.
"How did these kids build this thing?" asked Mark Greenwood, youth services officer for the Lafayette Police Department. "It was amazing ... We had to wrap a chain around the entire shack to get it down."
The flier did, however, let potential partygoers know two important facts: Beers were to be $2 and refills were only $1.
Before police tore it down, the shack was located about one-third of a mile from the end of Franklin Lane off Happy Valley Road. A clearly-defined dirt road ran into the park from Franklin Lane, hopping the curb, passing next to a neighbor's fence and just skirting a locked gate intended to keep vehicles out.
The start of the dirt track is immediately adjacent to neighboring houses, but the shack's location was completely isolated.
"It was so secluded that none of the residents around there would have heard these kids partying," Greenwood said.
The shack had only been operating as a party spot for about three weeks before police tore it out, said Acalanes junior Jon Ellery, adding he had never been to a party there. During that time those who built the shack would host a party "whenever somebody got liquor," he said.
But since it has been torn down, no one has heard of plans for a replacement, Ellery and other students standing around Acalanes after school one day agreed.
Lafayette typically has its party spots, Greenwood said, but nothing of this magnitude.
Although the shack's remote location meant no neighbors complained about loud parties there, he said, it also created more of a safety risk.
"It is a concern that the kids are that far out there in the middle of nowhere," Greenwood said, particularly with an open fire in a pit.
Survey data indicates that students in the Acalanes Union High School District binge drink more frequently than the state average.
Lamorinda has also seen two fatal accidents in the last year involving teenagers who had been drinking, wrecks which shook the community and prompted the "Slow Down Lamorinda" campaign.
Orinda modified its "unruly party" ordinance earlier this year, broadening the definition of an unruly party to make it easier for police to crack down.
Lafayette parent Joan Grimes pushed for a party ordinance earlier this year, but the effort gained no traction with the city, she said.
"The City Council made it pretty clear to me that they were not interested," she said.
And it's doubtful such ordinances would have any effect on a location like the shack, as they are designed primarily to hold parents responsible for what happens at their residences.
For Greenwood, a lot of the problems with underage drinking boil down to a simple question for parents: "Do you really know what your kids are involved in?"