Nemo 33 is the deepest indoor swimming pool in the world, located in Brussels, Belgium. Its maximum depth is 113 ft. It contains highly filtered spring water and holds several simulated underwater caves at the 10 metres ft) depth level. This is AWESOME!
Jason de Caires Taylor& underwater sculpture garden in Cancun. "Constructed out of concrete and steel, and bolted to the ocean substrate, the works here act as artificial reefs that provide & ideal habitat for filter feeding organisms.