It is a large military site and is situated north of the A48 road five miles (8 km) west of Chepstow and east of Newport. Since 1993 it has been used for a variety of military and civil purposes, including field exercises, car rallying, storage and breakdown of railway vehicles, nature preservation, and playing Airsoft. The site has its own standard gauge railway system (no longer linked to the national network), many private roads and a wide range of buildings, from small earth-banked stores to large four storey lightly built brick buildings. It is about two miles (3 km) east-west, and north-south. The perimeter road inside the security fence is, on its own, over seven miles (11 km) long.