It's an edible edifice made with over 1,000 pounds of sugar and gingerbread. It was unveiled on the day before Thanksgiving amid pomp and circumstance to a bevy of children staring with eyes and mouths open wide.
Munching on the fresh-baked cookies handed out before the ceremony, one dad quipped that it was a good thing snacks were provided, "because otherwise we'd be eating that castle behind us."
The tradition began 13 years ago when executive pastry chef Jean-Francois Houdre's children challenged him to build a gingerbread house that looked like a chateau from his hometown in France.
Now, his kids are grown, but the challenge remains - and it's become a year-round affair.
"Maybe two hours, one hour at a time, but every day," the castle gets a little work, Houdre said. "It's a non-stop project."
Now, there are two castles: a smaller one in the corner of the lobby is covered in white, sugary snow.
"It's really pretty, and it looks like a real winter wonderland," said 8-year-old Isabella Porcelli, visiting with her family from Tampa, Florida.
Though she admits she hasn't actually been to a winter wonderland, her older sister has seen castles in Romania, and confirms that the larger gingerbread structure is true to its medieval European roots.
Though Houdre insists it would be possible for one person to devour all the gingerbread that makes up the castle's towering walls, he points out the bread is extremely over-baked. It has to be dry to withstand the foggy, wet climate of San Francisco for its two months on display, he said.
As for the trees, turrets and tiny figurines - those are all pure sugar, of the type that's used to decorate wedding cakes. They're likely delicious - but the chef says he'd never take so much as a bite.
"Because if I do, it means I have to redo it. It's more work for me," he said.
The hotel knows the castles will draw a crowd, and hopes they're in the giving spirit. Surrounding this year's display are donation boxes for the American Red Cross, Guide Dogs for the Blind, Muttville Senior Dog Rescue and the Tenderloin Neighborhood Development Corporation.