Nemo33 is the current deepest pool in the world since it was open on the 1st of june 2004 and is situated in Belgium, Brussels.
The pool is divided is two pits, one of 10m and another of 33m depth. Between the pits there's a platafform at 5m and a underwater passage at 10m connecting the two pits. In this underwater passage there's is also two decorated air-caves.
The water is very clear and warm (arround 32ºC) with a good visibility to the bottom and without chlorine smell.
It's possible to take scuba-diving courses in this pool, but freediving is limit to the 10m pit.