Hold your breath: The world's deepest pool goes 137 FEET below the surface and is filled with crystal clear 32C spa water
- 'Y-40 Deep Joy' is located at the Hotel Terme Millepini in Italy
- The pool is 21m by 18m at the surface, but narrows -40m
- The 4,300 cubic metres of thermal water averages 32-34°C
- The Y-40 overtook Brussels' Nemo33 as the world's deepest pool
- It is used for free diving and scuba diving training and recreation
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 is open 365 days a year for deep sea diving training, leisure dives and photoshoots. Wet suits aren't required here as swimmers can enjoy a regular temperature of between 32-34°C.
Scroll down for video
Record breaker: Y-40 The Deep Joy is the world's deepest pool with a staggering depth of -40 metres
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.
There is also a unique suspended underwater tunnel which is entirely transparent, so non-swimmers can experience the pool without getting wet.
There is a sunbathing deck with loungers on the roof, where swimmers can recover from their deep-diving experience.
Dry dock: The underwater tunnel runs right through the middle of the pool
Plunging: A diver is filmed from the depths of the Y-40
Overtaken: The Y-40 surpassed the Nemo33 in Brussels, Belgium
Afraid of depths? The pool features several depth platforms before narrowing into a deep descent
Activities: As well as free diving, the pool offers opportunities for scuba divers to practice cave diving
Other-worldly: Free diver Ilaria Molinari dresses as a mermaid to swim through the artificial cave-diving area
Launch: Molinari dove the depths of the pool at its opening with the help of a mermaid's tail
Spectator sport: A 13-metre transparent tunnel allows non-swimmers to experience the pool
Temperate: 4,300 cubic metres of thermal water are kept at a temperature of 32-34 degrees celcius
Notable figures from Italian water sports helped to launch the facility this year, including Italian free diver Umberto Pelizzari, and Enzo Maiorca, the ‘father’ of freediving in Italy.
Freediver Ilaria Molinari even donned a mermaid tail to dive down to 40 metres to wow spectators.
'Y-40 is unique in its field thanks to the spa water, which cannot be outsourced,' says architect Emanuele Boaretto. 'We want to open up new medium and long term work prospects to try and guarantee prosperity, not only for my company but also for the surrounding land and society.'
Architectural marvel: The pool is designed by renowned architect Emanuele Boaretto
Tourist attraction: Y-40 The Deep Joy is housed within the four-star Hotel Terme Millepini