Kameishi

Kameishi (Tortoise Stone) is a massive granite megalith in Asuka village, Nara Prefecture, carved into the shape of a turtle. The stone currently faces south, but legend holds it originally faced east, and if it ever turns west, all of Japan will be reduced to a sea of mud. When, how, or why it was carved remains unknown, like many of the mysterious stone monuments scattered across Asuka. One theory interprets it as an ancient star chart mapping the constellation Cassiopeia.