Patomskiy Crater

The Patomskiy crater or Patom crater, also known as Конус Колпакова, Konus Kolpakova "Kolpakov cone") is a peculiar rock formation located in the Bodaibo District of the Irkutsk region of southeastern Siberia, 360 kilometres from the district center Bodaibo. It is a large mound made of shattered limestone blocks on the slopes of the Patom Highlands in an area of dense taiga. Its base diameter is about 160 metres and its height about 40 metres; the cone's crown is ring-shaped, and in its center there is a smaller mound with a height of about 12 metres. The volume of the crater is estimated as 230,000–250,000 cubic metres, with a weight of about one million tons.

The Patomskiy crater was discovered in 1949 by Russian geologist Vadim Kolpakov. Its origins have been subject of intense scientific interest, with hypotheses including meteorite, volcanic and gaseous origin, but to date no definite proof has been given.