Written by 
Once upon a time, over a thousand years ago, a Buddhist monk named Yūkei was traveling across the Adachi-ga-hara plain when he sought a lodging for the night and found a cavern occupied by an old woman. She agreed to accommodate him on condition that he does not look inside the chamber at the back while she was away to fetch some firewood.
As always expected in such tales, however, curiosity got the best of Yūkei. What he found was a scene of horror—a mountain of human bones. Remembering the rumors of a cannibal hag, Yūkei ran away from the cavern, only to be discovered by the hag herself and pursued. As he was about to be killed, the monk prayed to Cintamicakra, who manifested as a ray of light that annihilated the monster. To thank the bodhisattva, Yūkei founded a temple on the site and built a mound for the hag which would come to be known as Kurozuka, or the Black Tomb.
Known across Japan for centuries, the legend inspired numerous works of drama and literature, including the popular 15th-century noh play Kurozuka and its sci-fi retelling Adachi-ga-hara written in 1971 by manga legend Osamu Tezuka.
Today, the storied Black Tomb can be found in the city of Nihonmatsu, Fukushima Prefecture, just off the grounds of Kanze-ji Temple founded by Yūkei. The mound is topped by several funerary stelae and a tall tree, standing by the Abukuma River as spookily as can be.