Atlantis II Deep,  submarine basin, the largest in the Red Sea, located at latitude 21°23′ N and longitude 38°04′ E. The Atlantis II Deep attains a maximum depth of 7,160 feet (2,170 metres)

Atlantis II Deep is noteworthy because it is one of the areas containing hot brines, with water temperatures ranging up to 133 °F (56 °C) and salinities to 270 parts per thousand, which is about 7 ¹/₂ times that of normal seawater. Metallic trace elements, such as zinc, copper, and cobalt, are present in concentrations exceeding those of normal seawater by about 1,000 times. The upper 33 feet (10 metres) of sediment in the Atlantis II Deep, which at places is 300 feet (90 metres) deep, contains economically highly valuable metal deposits. Similar but somewhat smaller basins known to exist in the Red Sea are Chain Deep and Discovery Deep, with maximum depths of 6,778 and 7,283 feet (2,066 and 2,220 metres), respectively.