What Guards the Largest US Nuke Site? Duh!!: ROBOT SENTINELS ... & I'm not kidding

Fully automated robots now guard the Nevada National Security Site. These robotic sentinels are completely autonomous, capable of identifying human intruders as well as detecting broken locks around the site's perimeter. In fact, these diesel-powered centaurs can operate for a maximum of 16 hours, which give them plenty of capacity to patrol the most extreme corners of the 1,360-mile facility—larger than the state of Rhode Island. The base includes 28 areas, 1,100 buildings, and 700 miles of road, as well as ten heliports and two airstrips.

When the MDARS bots find an anomaly, they alert their human master. However, it's not hard to imagine these metal beasts equipped with non-lethal weaponry in the near future.