Bulla Island

Bulla Island (Kharra Zira, Azeri: Bulla adası (Xərə Zirə)) is an island in the Caspian Sea. It is the largest island in the Absheron Peninsula region off the Bay of Baku, Azerbaijan.
en.wikipedia.org/wiki/Bulla_Island
Mud volcano.
Main volcanic activity episodes were observed in 1810, 1857, 1859, 1940, 1947, 1959, 1960 and 1963. The strongest eruptions occurred in 1857 and 1940, when volumes of erupted breccias attained some millions of cubic meters and flame pillars were up to a kilometer high.
The most interesting mineralization (native metals, akdalaite) is connected with ejecta of 1947 eruption.
In 1930 and later the island with others nearby served as the execution place for NKVD (State Political Police).