Derelict Graveyard-The one big one that usually referenced is the Kaladros Wastes. On the edge of the frontier between the Griffin Moot and Equestria, both nations maintained garrison forces on the only world in the system, and warship fleets in the space surrounding the Wastes. They did this even during the Horizon War, and kept the neutrality of the location throughout the War.
The reason for this is simple-the Kaladros Wastes is a Precursor graveyard. The job of the fleets and the garrison is not to keep scavengers and unauthorized exploration parties out. They do this, mind you, but it’s not their primary job.
Their primary job is to keep whatever is in the Kaladros Wastes in.