Opened in 1927 as a beaux-arts-style memorial to those who served in WWI, the Natatorium has a saltwater pool that's 100m long and 40m wide. Unfortunately, its current condition is an indictment of bureaucratic neglect: the city and county of Honolulu assumed control of the site in 1949 and allowed it to deteriorate until it was closed in 1961.
The condition of this historically registered landmark has continued to deteriorate in the decades since.