Blackstone Edge ( ) is a gritstone escarpment at 472 m (1,549 feet) above sea level in the Pennine hills surrounded by moorland on the boundary between Greater Manchester and West Yorkshire in England. History Crossing the escarpment is Blackstone Edge Long Causeway, also known as Blackstone Edge Roman Road, a partially paved road on the Greater Manchester side, becoming a holloway through peat as it runs into Yorkshire. The Blackstone Edge Long Causeway was originally thought to be of Roman origin until investigations by James Maxim, who proposed the theory that it was actually a 1735 turnpike or packhorse route. This theory was widely accepted until 2012 when investigations by Archaeological Services WYAS led them to conclude that "The archaeological surface evidence...suggests that the route of the road is unlikely to have originated as part of a turnpike scheme as probable medieval and post-medieval features, including a packhorse road, appear to overlie the substantial road cuttings in a number of places. If the road does not originate in the 18th century, then the scale of construction of the road cuttings suggest a level of engineering skill, planning and use of resources only otherwise normally associated with Roman roads." This report confirms the original Roman date. The route is designated as a scheduled monument in both Greater Manchester and West Yorkshire. The Aiggin Stone, a gritstone pillar, possibly a way-marker, stands alongside the road, which may also have seen later use as a 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. Much of the surrounding area was within the ancient parish of Hundersfield, although some parts lay within Butterworth township. In the English Civil War the Parliamentarians sent 800 men to fortify Blackstone Edge; John Rosworm came from Manchester to direct the construction of defences. It was successfully held against an attack by Royalist cavalry. In 1660 the churchwardens of St Chad's paid 24 shillings for eight loads of "great stones from Blackstoneedge" for Rochdale church steps. Celia Fiennes travelled over Blackstone Edge and described her journey in about 1700. A meeting of supporters of Chartism from the surrounding industrial towns of Lancashire and Yorkshire was held in 1846, attracting up to 30,000 people. Sport Blackstone Edge is frequented