Are you Godzilla? Most people are, at least some of the time. The nice people at the Cardboard Institute of Technology understand this, and in the past, they've created huge miniature (not an oxymoron) cities for you to dominate, roar in, and ultimately destroy, most of which were named Cardburg. The group's new huge miniature goes up at the Exploratorium, is called Sub-Terrain, and needs you to help build it, you big lizard. From now until March 5, go to the Tinkering Room and glue cardboard into subways, catacombs, sewers, tunnels, basements, Bob Dylan, and we're just making shit up off the top of our heads on the theme of subterranean, which is what you're supposed to do when you get there.