Syukeyevo Caves were a group of cave

Cave

A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...

s in what is today Kamsko-Ustyinski District, Tatarstan

Tatarstan

The Republic of Tatarstan is a federal subject of Russia located in the Volga Federal District. Its capital is the city of Kazan, which is one of Russia's largest and most prosperous cities. The republic borders with Kirov, Ulyanovsk, Samara, and Orenburg Oblasts, and with the Mari El, Udmurt,...

, Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. Located near the village of Syukeyevo

Syukeyevo

Syukeyevo is a village in Kamsko-Ustyinsky District of the Republic of Tatarstan, Russia, located on the bank of the Mordovskaya River , 23 kilometers south-west of Kamskoye Ustye, the administrative center of the district. Population: 750 ; 792 ; all ethnic Russians. There is a secondary school...

 until the 1958, they were destroyed by an eruption of the banks of the newly filled Kuybyshev Reservoir.

There were several minor and three notable caves, the biggest Maiden Cave was 120 m long and 14515 m³ in volume. The second notable, Minor Syukeyevo Cave was 70 m long and 734 m³ in volume. Both caves had a dolomite

Dolomite

Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

 top and a gypsum

Gypsum

Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...

bottom.