Peeking down over the edge of the start of the Bridge Valley Path you can just make out the entrance to the Portnalls railway tunnel under Bridge Valley Road. It opened in 1865 and ran to Avonmouth from a terminus in Hotwells, but was closed to enable the construction of the Portway in 1922 (source: Peaceful Portway "Memorable Walks" leaflet)
GPS Coordinates:
51.45750, -2.62919
Location: Clifton Down