Mezmaiskaya Cave (Russian: Мезмайская пещера) is a prehistoric cave site overlooking the right bank of the Sukhoi Kurdzhips (a tributary of the Kurdzhips River) in the southern Russian Republic of Adygea, located in the northwestern foothills of the North Caucasus in the Caucasus Mountains system.
Three Neanderthal individuals were recovered from the cave. The first, Mezmaiskaya 1, was recovered in 1993 and is an almost complete skeleton in a well preserved state due to calcite cementation that covers and holds the arrangement in place. It was assessed to be an infant about two weeks old, making it the youngest Neanderthal ever recovered. Although no burial pit was found, circumstances suggest that the body was buried intentionally, explaining the good state of preservation and the lack of scavenger marks. Mesmaikaya 1 was recovered from Layer 3, the oldest Late Middle Paleolithic layer at the site. Mezmaiskaya 1 is indirectly dated to around 70–60,000 years old.
Additionally, 24 skull fragments of a 1- to 2-year-old Neanderthal child - Mezmaiskaya 2 - were found in 1994. A recovered tooth was assigned to Mezmaiskaya 3. Mezmaiskaya 2 was recovered from Layer 2, the youngest Late Middle Paleolithic layer, and directly dated to around 44,600-42,960 cal BP. DNA analysis reveals that Mesmaiskaya 2 was male.