Kigilyakh or kisiliyakh[1] (Russian: кигиляхи; Yakut: киһилээх, meaning "stone person") are pillar-like natural rock formations looking like tall monoliths standing more or less isolated. Usually they are composed of granite or sandstone shaped as a result of cryogenic weathering.[2] Most kigilyakhs formed during the Cretaceous period and are about 120 million years old.[3]