Nemo 33 is a recreational diving center in Brussels, Belgium

The pool itself consists of a submerged
structure with flat platforms at various depth levels

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

There are numerous underwater windows that allow outside visitors to look into the pools at various depths

designed by Belgian diving expert John Beernaerts as a multi-purpose diving instruction, recreational, and film production facility, and opened in 2004

You are not allowed to practice any skills unless you have an instructor in your group