Kigilyakh

thumb|300px|Kigilyakhs in the Ulakhan-Sis Range thumb|300px|Kigilyakhs on Chetyryokhstolbovoy Island, East Siberian Sea

Kigilyakh or kisiliyakh (; , plural kihilēxlere) 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. Most kigilyakhs formed during the Early Cretaceous and are about 120 million years old.