During the First Galactic War, the Colonial Marines constructed hidden bases in remote locations throughout the planetary network. These self contained bases were mostly built in the sides of mountains or deep underground to house first response teams that were ready to identify and eliminate any possible invading races.
After the war years were over, these bases were abandoned and became ideal hideouts for smugglers, bounty hunters and others who would rather not be in the spotlight as they were both off the beaten path and extremely difficult to breach. Plus, the lifetime Solithium power cells and deep water wells they were built over meant a resident could live well off the grid.