Apart from jigoku steamed eggs which are steamed in a stone steamer which utilizes steam from a hot spring, at Umi jigoku hot springs on the Beppu Jigoku (Hell) Tour, the specialty is jigoku boiled eggs which are eggs that have been put in bamboo baskets and put directly into the 98℃ cobalt blue hot springs.
温泉の蒸気熱を利用した地獄釜で蒸す地獄蒸し卵の他、別府地獄めぐり海地獄では、98度のコバルトブルーの温泉に、竹籠に入れた卵を直接浸してゆでた、地獄ゆで卵が名物となっている。