The Devil's Den is a bit of a curiosity. It is hard to find and involves hiking through fields with an ordnance survey map, as it is on private land and not signposted. It is a dolmen burial chamber, or at least looks like one now, with two standing stones and a capstone on top, but closer inspection reveals some rather modern cement holding the upper stone in place. Apparently this is all that is left of what was once a 230 foot long barrow that has since been ploughed over.
While driving out of Warminster towards Salisbury there are some hills on the left side of the road. One of them has a prominent barrow on the summit with a mysterious pole sticking out of the top of it. This was enough to pique my interest for a visit, but a little research identified this as a prime candidate for Hidden Wiltshire. This is Scratchbury Camp, an iron age hillfort on the edge of Salisbury plain which is archaeologically significant. As you walk up it you will e