The Dunes Caves are found inside the Giant Sinkhole around the thermal vents in the Dunes biome.
The Dunes Caves feature Fauna such as Rockgrubs or Cave Crawlers, also inhabitants of the Dunes. Only three of these caves exist. Large Resource Deposits can be frequently seen here, with Ruby and Lithium close to their entrances.
Four of the fourteen Sea Crowns on the map can be found in these caves.