Bathyscaphe Trieste
Trieste is a Swiss-designed, Italian-built deep-diving research bathyscaphe, which with its crew of two reached a record maximum depth of about , in the deepest known part of the Earth's oceans, the Challenger Deep, in the Mariana Trench near Guam in the Pacific. On 23 January 1960, Jacques Piccard (son of the boat's designer Auguste Piccard) and US Navy Lieutenant Don Walsh achieved the goal of Project Nekton.
Hotel Terme Millepini
Y-40 "The Deep Joy" pool first opened on 5 June 2014 and was designed by architect Emanuele Boaretto. It is deep, making it the deepest pool in the world. It contains 
of thermal water kept at a temperature of . The pool features underwater caves and a suspended, transparent, underwater tunnel for guests to walk through. It includes platforms at various depths, ranging from to , before the walls of the pool narrow into a well-like funnel which plunges straight down to . The hotel offers tickets to freedive and scuba dive. Italian freediver Umberto Pelizzari first measured the depth before the pool was open.