Bucketlist: Nemo 33 is the deepest pool in the world. The pool is located in Brussels, Belgium. Its maximum depth is 113 ft. It contains 2.5 million liters of non-chlorinated, highly filtered spring water maintained at 86 °F and holds several simulated underwater caves at 33 ft. There are numerous underwater windows that allow outside visitors to look into the pool at various depths. And it costs roughly $28 for a dive. Done.