Deep Dive Dubai is four times deeper than any pool in the world and if you make it to the bottom, you will find a hidden treasure.
From DeepDiveDubai.com:
This extraordinary indoor pool is filled with 14 million liters of freshwater, the equivalent of six Olympic-sized swimming pools. Water is kept at 30 degrees to create the perfect conditions for diving – and there’s no need to wear thick wetsuits. Your dive at Deep Dive Dubai will never be cancelled due to weather conditions, avoiding all the dangers of diving in rough seas.