Hugo Lisoir has delivered his caves. They have been integrated.
With our system, it is impossible to datamine the caves, so nobody knows where they are (apart from a handful of people you could count on the fingers of one hand).
Here are a few hints anyway: there is at least 1 cave within a 15 km radius around each M0xxx mining village.
To push you to explore and find caves, when you find a cave that has never been found before, the game offers you to name the cave however you want and that will persist (unless we remove persistence entirely, but we will try to keep them as long as possible).
ARES will have to validate the name, so don't go too silly or it will be rejected 😉