Nemo 33 is a recreational diving center in Brussels, Belgium that
is home to the world's deepest swimming pool. The pool itself
consists of a submerged structure with flat platforms at various
depth levels. The pool has two large flat-bottomed areas at depth
levels of 5m (16 ft) and 10m (32 ft), and a large circular pit
descending to a depth of 33m (108 ft). It is filled with 2,500,000
litres of non-chlorinated, highly filtered spring water maintained
at 30°C (86°F) and contains several simulated underwater caves
at the 10m depth level. There are numerous underwater windows
that allow outside visitors to look into the pools at various depths.
The complex was designed by Belgian diving expert John Beernaerts
as a multi-purpose diving instruction, recreational, and film
production facility, and opened in 2004.