In Broward County...the description going with the picture (from FaceBook) reads:
"A favorite beach-side destination for local children in the 1950s was the Casino Swimming Pool. Opened in 1928 at what is today A1A and SE 5th Street, it included an Olympic-sized pool filled with ocean water. The site of the annual College Swim Forum and many national competitive events, the facility was demolished in 1966 after the completion of the Swimming Hall of Fame."