So thinks the photographer, Troy Holden.
From the Flickr set:
After years of deterioration and absence of modern operational systems, the [Fleishacker] pool did not meet health and safety standards and closed in 1971. Consideration was given to refurbishing and reopening the historic landmark, but usage studies showed low interest, and the high annual operating costs could not be offset with the expected revenue. In 1999, the San Francisco Zoological Society was granted ownership of the pool house, and it is not known what might become of it. The swimming pool itself was filled with rocks and gravel, with the space now serving as a parking lot for the zoo.