The Y-40 Deep Joy is the worlds deepest pool. Y-40 is projected by Architect Emanuele Boaretto and supported by the “Boaretto Group Hotel and Resort”. The name Y-40 is inspired by mathematical symbols. “Y” is the ordinate axis of the Cartesian system and “–40” means the world's record depth or our pool- that is 40 meters underground. (Photo by Courtesy Y40 Deep Joy)

An octopus is filmed by the National Oceanic and Atmospheric Administration ship Okeanos Explorer and its robotic sub. (Photo by National Oceanic and Atmospheric Administration)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

p*rn star Linda Lovelace, who starred in “Deep Throat”, arrives at the Academy Award in Los Angeles, Ca, April 3, 1974. (Photo by AP Photo)

Sunrise over Maridalsvannet in the forest areas near the outskirts of Oslo, the capital of Norway. Winter is approaching, the first snow covers the ground, and the water has already got a thin layer of ice. The temperature is significantly below the freezing point, the air is clear and the sun colors the morning clouds in deep tones. (Photo by Tore-Thiis-Fjeld/Getty Images)

Sikh Nihang (Sikh warriors) perform “Gatka”, an ancient form of Sikh martial arts, during the “Nagar Kirtan” procession to mark the 339th birth anniversary of the Sikh warrior Shaheed Baba Deep Singh, in Amritsar on January 31, 2021. (Photo by Narinder Nanu/AFP Photo/Profimedia)

A Sri Lankan fisherman tries to push back stranded pilot whales into the deep water in the northwestern coast of Kudawa on February 11, 2023. Eleven pilot whales were saved on February 11 after beaching on Sri Lanka's western coast in the early hours, wildlife officials told AFP. (Photo by AFP Photo/Stringer)