Batu (pronounced BAH-too) is an immense caldera on the southernmost major island of the Nests, an archipelago within the Wounds. The volcano is not actively erupting, and has never within the time of oral histories, but any approach to it is perilous nonetheless. The barren expanse of black igneous rock that surrounds Batu holds an invisible danger, as the air there is laden with toxic fumes released from the ground that will quickly fell any person or creature that attempts to travel through.
Perhaps because of these dangers, Batu is one of the largest Ha-Kolawa nesting grounds, with a great many of the pterosaurs returning regularly to the caldera to lay and guard their young, with the knowledge that they are safe from most predators on the ground.