Balboa Park is a 1,200-acre historic park in San Diego. It hosted the 1915 to 1916 Panama-California Exposition and the 1935 to 1936 California Pacific International Exposition, and both left landmark buildings behind. The park was named a National Historic Landmark District in 1977.
The Botanical Building was built for the first exposition and remains one of the largest lath structures in the world. Alfred D. Robinson, founder of the San Diego Floral Society, suggested a lath house for the fair. A garden and lily pond were built in front of it in 1915.
During World War I and World War II the navy used the pond for swimming lessons. The building closed in 2021 for renovations and reopened in December 2024.