Octopus stone
Geologic formation in Japan
From Wikipedia, the free encyclopedia
The octopus stone, Taiko-ishi 蛸石 (also called "Drum Rock") is a large stone at Osaka Castle in Japan. The stone is near Sakura Gate.[1]

It is one of the largest of several megaliths at the castle (by face area), at 5.5×11.7 meters and over 120 tonnes (130 tons).[2][3] Its name is derived from the octopus shape visible on its lower left corner.[4]