Passing the crag is Blackstone Edge Long Causeway, also known as Blackstone Edge Roman Road, a paved road originally thought to be of Roman origin. After investigations by James Maxim it is now considered to be a 1735 turnpike or packhorse route. The Aiggin Stone, a gritstone pillar, possibly a way-marker, stands alongside the packhorse route and marks the county boundary. The stone has a cross and the letters I and T cut into it. Its name is said to derive from the French aiguille for a needle or aigle for an eagle.