The world's deepest pool which is the height of nine double decker .

If you can hold your breath all the way to the bottom here, you are in a very small minority - this is Y-40 The Deep Joy and with a staggering depth of -40 metres it is the world's deepest pool.

The incredible swim centre, designed by renowned architect Emanuele Boaretto, is located within the four-star Hotel Terme Millepini in Montegrotto Terme, Italy.

Operating since June, the pool has a diving height of a 12-storey building, or nine double decker buses placed on top of each other.

Wet suits aren't required here as swimmers can enjoy a regular temperature of between 32-34°C.

There are several platforms, ranging from -1.3m, to -12m. The pool at the surface is 21m by 18m but it becomes a narrow well-like hole as the depths plummet straight down.

Visitors are able to use the facilities for free diving and scuba diving, with underwater caves for cave diving beginners