Labynkyr Lake, Protected lake in Oymyakonsky Ulus, Sakha Republic, Russia

Labynkyr is a body of water in Oymyakonsky Ulus, Sakha Republic, that stretches across more than forty square kilometers and reaches depths beyond fifty meters in some sections. The surroundings consist of rocky terrain with sparse vegetation and wide views of the surrounding mountain ranges.

The first written record of the lake monster comes from geologist Viktor Tverdokhlebov, who observed a large moving object on 30 July 1953. Diatom sampling began in 1961 and identified 79 species. In 2005 a TV expedition used sonar to map an anomalous trench on the floor; in March 2013 divers Dmitry Shiller and Alexander Gubin reached 59.6 m under the ice.

Yakut locals call the creature the Labynkyr Devil, describing a dark grey animal with a huge mouth, eyes set as far apart as the width of a ten-log raft. Legends say it attacks people and animals and can leave the water. The earliest written account is by geologist Viktor Tverdokhlebov in 1953.

The lake lies in Oymyakonsky Ulus near the borders of Khabarovsk Krai and Magadan Oblast. In March 2013 the expedition reached it by modified KAMAZ trucks driven across the ice, covering 30 km in about 20 hours. Winter air has been recorded at -60 °C while the water stays near +2 °C; summer can reach 35 °C.

The lake's central island, about 30 m across and 5–6 m high, is said by locals to vanish beneath the surface now and then, though the water level barely changes; the effect is probably optical, like a mirage.