Summary:

Koppa Mining Site is an aquatic, cavernous biome located under the Delta Island. It is accessible from the Thermal Spires on the western side of the island, either through a partially-opened door or via a crevice blocked by two magma vents. It consists of Main Shaft which leads to mine systems and another shaft that can only be accessed through a small gap in the northeastern corner of the hall containing the Main Shaft. The Secondary Shaft is filled with sand and doesn't lead to any cave system. A Prawn Suit with a drill arm is recommended for optimal gains from the Mining Site, but cannot fit into the room with an Architect Artifact.