Reaching up to 113 feet (34.5 meters) in depth, Nemo 33 isn’t your ordinary swimming pool.
It’s actually a diving pool, built by Belgian diving expert John Beernaerts in 2004 for training scuba divers. Nemo 33 holds 2.78787 million liters of filtered spring water kept at a constant temperature 30 °C (86 °F) and contains concrete rooms 33 feet (10 meters) beneath the surface to simulate underwater caverns.
The pool walls also contain windows which provide a view of the divers from the Nemo 33 Diving Restaurant. The fascinating display looks fairly like a human aquarium, which is pretty cool. Besides PADI courses, Nemo 33 is also a favorite destination for shooting underwater films.
You can dive in Nemo 33 in Brussels, Belgium at a starting fee of 22€.