I'm sure any spot would do, Digging down and around is bound to find caverns and possibly a few cave neighbors unwilling to give up their homes with the intrusive lights that will get set up throughout the area

My general plan is just to set up a mediocre building in the beginning, set up an underground base that is just under the ground that would have step mines in a couple direction to the bottom of the map. To keep any basements or underground building safe from accidental crossing I would keep low and preferably out of the way of the main town section of course.