At first glance, you would think this place is some sort of abandoned and flooded science facility but it's actually much cooler. This is intact Nemo 33, the worlds deepest man-made pool. The pool is located in Brussels, Belgium. At its deepest, it is 34.5 metres which is 113ft. It is filled with 2,500,000 litres of non-chlorinated spring water. It also has several simulated underwater caves at the 10 metre (33 ft) level.