The A625 previously ran, undiverted, between Castleton and Chapel-en-le-Frith, winding its way up the south face of Mam Tor—replacing a much earlier route through the Winnats Pass. This section of the road proved highly prone to landslides, especially after periods of heavy rain, and was in constant need of repair. It was finally abandoned in 1979 and traffic was, once again, directed westwards through the Winnats Pass.