Ocean ruins are submerged relics that often contain valuable loot such as enchanted books, emeralds, buried treasure maps, and enchanted fishing rods. They are typically covered by sand or gravel, presenting opportunities for archaeological exploration. These ruins are guarded by underwater zombies known as drowned, which may attack with their hands or tridents. A strategy for accessing these treasures involves finding ruins near magma blocks, which create bubble columns for a quick descent, although ascending back to the surface can be more challenging.