人通りの少ない旧八万地獄の歩道から、すこし外れた場所に巨大な岩「鬼石」がある。
息を止めて、一周できると願い事が叶うとか、、。古い雲仙の絵図面に、鬼石の場所が明記されてあり、温泉山縁起にも、「此の山ノ本主、歓羅は、四面ノ大鬼ナリ。行基菩薩ニ遇ヒ奉リ、種々ノ問答アリ。又、鬼アリ、男鬼ノ名ハ、空仙鬼、女鬼ノ名ハ、難林王ナリ。此の鬼々ヲ加持スレバ、即チ鬼石トナル」と記されてある。
　小浜の鬼石は、男鬼の空仙鬼、雲仙の鬼石は、女鬼の難林王ではないかと思われる。
英語バージョン
「Oni(demon)-ishi」
In a slightly secluded location, away from the old Onsensan map Hell's path with little pedestrian traffic, there is a giant rock called "Oniishi" (Demon Stone). It is said that if you hold your breath and make a complete circle around the stone, your wish will come true. The location of the Oniishi is specified in old Onsensan maps, and in the Onsensan Enki (legend of Onsensan), it is written, "The main deity of this mountain, Kira, is a great demon with four faces. He had various conversations with the bodhisattva Gyōki. There are also demons, and the male demon is called Kuusenki, while the female demon is called Nanrin-ō. If you possess these demons, they will become the Oniishi."The Oniishi in Obama is believed to be inhabited by the male demon Kuusenki, while the Oniishi in Onsensan is thought to be the dwelling place of the female demon Nanrin-ō.