Location from Gravity Falls by Alex Hirsch / Disney Channel
Grunkle Stan's tourist trap, home base of the Pines family's summer, and a building with three basement levels hiding thirty years of secrets beneath the gift shop floor.
The Mystery Shack is both exactly what it looks like and not at all what it looks like. On the surface: a tourist trap full of fake exhibits, a gift shop with overpriced merchandise, and a tour narrated by a man who invented most of the 'mysteries' himself. The admission is eight dollars. The 'genuine dinosaur fossils' are painted plastic. The tourists usually know. Stan charges them anyway. Beneath the gift shop, through a trapdoor Stan knows and no one else was supposed to, is a laboratory that predates the tourist trap. Ford built it first. Stan built the Shack around it and spent thirty years using it to rebuild the interdimensional portal. The tourists never went near the basement. The basement was the whole point. The Shack's address is 618 — June 18th, creator Alex Hirsch's birthday. The forest presses in on three sides. The goat Gompers lives on the property and eats things that should not be edible.
A ramshackle cabin at 618 Gopher Road — technically occupying over three square miles, with two upper floors and three basement levels that go deeper than the outside dimensions suggest are possible. The 'S' in the 'Mystery Shack' sign hangs sideways, permanently making it read 'Mystery Hack.' A totem pole out front. The gift shop smells like old carpet and Stan's aftershave.