The Chinatown exhibit on the Isthmus during the Panama-California Exposition of 1915 contained a 'Joss House" underground, simulating an "opium den." The Toadstool was a spinning disk ride. This was the "Fun Zone" or "Amusement Zone" of the Exposition, held in Diego's Balboa Park to celebrate the completion of the Panama Canal. The Isthmus occupied a part of the park now covered by the parking lot of the San Diego Zoo.
