The Pentland Hills, just south of Edinburgh, are home to a number of forts, including Castlelaw Hill Fort. It is a multi-ramparted hill fort that was occupied throughout second half of the first millennium BC. Possibly in the 2nd century AD, a stone-lined souterrain – or an earthhouse – was built into the ditch near the east entrance to the now abandoned hill fort. This is now covered with concrete.
The fort is approximately 150m long and 100m wide, with two ramparts that were accompanied by a rock-cut ditch, as well as an external counterscarp bank. The ramparts had breaks in them, which suggests that there were three entrances to the hill fort.
There have been two archaeological excavations of the site, one in 1931/2 and another in 1948. These excavations revealed information about the defences used over different occupations of the fort. Future archaeological investigations could shine a light on the Iron Age period in southern Scotland.
Castlelaw became a Scheduled Ancient Moment in 1924 and is now under the care of Historic Environment Scotland, follow their link for more information. It now lies within a working farm.