One Piece Odyssee

Punk Hazard is one of the first three Islands of the Grand Line. The island is surrounded by a sea of fire on one side and icebergs on the other. In the center, there is a hole where seawater flows into it, which separates both halves of the island and has sharks living within. This lake was originally a crater formed at the epicenter of Akainu and Aokiji's death match and then later filled with seawater, though the aftermath of the duel did leave behind patches of burning and frozen waters in the lake