Located in a basement in San Diego’s Balboa Park is the nondescript San Diego Model Railroad Museum. The museum usually attracts model railroad enthusiasts and little kids who love Thomas the Tank Engine, but it’s also a lively alternative to some of the more common museums in Balboa Park.

Opened to the public since 1982, the 27,000-square-foot museum is the largest indoor model railroad collection in the world and the only accredited museum of its type in North America. The museum aims to educate the public on the history of railroading and also to preserve the meticulous craft of building model railroads.

Each museum exhibit is sponsored, built, and maintained by several San Diego-area model railroad clubs. Volunteers head to the museum on weekly work nights to design and construct scenes that capture the history of California’s railroads. Some of the more elaborate exhibits feature detailed landscaping and wooden bridges that take hundreds of hours to complete. Look closely and you’ll find hidden scenes that the clubs put in for laughs: Is that a shark in the swimming pool? Is there actually someone sitting down on that toilet?

Guests are encouraged to head back to the museum on a regular basis, as the exhibits are ongoing projects and always changing.