The view down into the deep pit at Nemo 33 Nemo 33 is an indoor non-chlorinated fresh water facility in Brussels, Belgium. It held the record as the deepest indoor swimming pool in the world between its opening on May 1, 2004 and the completion of Y-40 in Montegrotto Terme, Padua, Italy on June 5, 2014.
The Seagaia Ocean Dome was closed as due to renovation and re-branding efforts. 8. Piscine Alfred Nakache, France. Built on Ramier Island in the midst of Toulouse, France, the Piscine Alfred Nakache, named after the legendary swimmer, consists of two pools. One is an indoor public swimming pool and is used in winter.