The name for such a hole is "caldera" which is a word of Spanish origin meaning "a pot" or a "cooking pot" (thing of cauldron!) - and this word is used because it resembles the shape of this hole.
Often the Calderas are filled with water forming lakes and often there is an island in the middle of the water.
It was divided because of the tensons between the allies and soviets
Answer:
Physioeconomically, the Russian Federation may be conveniently divided into 9 major regions: the Central European Region, the North and Northwest European Region, the Volga Region, the North Caucasus, the Ural Region, Western Siberia, Eastern Siberia, Northern and Northwestern Siberia, and the Russian Far East.
Explanation: