An indoor pool in Italy is slightly terrifying.
It was designed by architect Emanuele Boaretto and is located in Hotel Terme Millepini near Padua, Italy. According to the project’s website, Boaretto’s goal was “to build the best swimming pool in the world.”
While that measurement is subjective, the pool is Guinness World Records-certified as the world’s deepest swimming pool for diving.
Y-40’s name is a reference to its depth, with the “-40” meaning that the pool plunges about 40 meters, or about 131 feet, at its deepest.
According to Guinness, it holds 1,135,939 gallons of thermal water, and is “used for dive training, leisure diving and scientific research.” It’s easy to visit the hotel and explore the adjoining Y-40 pool, as you can just sign up to book a hotel room and a dive at the same time.