Border outpost

A border outpost, border out post, border observation post or BOP is an outpost maintained by a sovereign state on its border, usually one of a series placed at regular intervals, to watch over and safeguard its border with a neighboring state with which it may or may not have friendly relations. Such posts are staffed by border guards and are at all times connected by radio communication with ongoing border patrols in their region and the force headquarters in the interior of the country for their day-to-day functioning, passing on intelligence and for requesting supplies and any needed reinforcements in emergencies.

This keyword could refer to multiple things. Here are some suggestions: