Caves and caverns are natural or artificial cavities in the ground. They are generated by plaque tectonic mechanics, weathering or artificial excavation.
Speleology is the science of exploration and study of all aspect of caves and the cave environment.
Mining is a profitable activity that can be performed in a cave. Every cave offers opportunities to use the multitool, while the biggest caverns allow a ROC or even an ARGO MOLE to enter them.
Another profitable activity, depending on the celestial body where the cavern is located, is the collection of harvestables.