Lava Tubes!!
District 13
Despite their larger size, the researchers believe that the lava tubes are surprisingly stable, meaning settlers wouldn’t have to worry about them collapsing around them.
“Lava tubes could provide stable shields from cosmic and solar radiation and micrometeorite impacts which are often happening on the surfaces of planetary bodies,” European Space Agency researcher Francesco Sauro said in a press release. “Moreover, they have great potential for providing an environment in which temperatures do not vary from day- to night-time.”