Cork, Bandon and South Coast Railway (CB&SCR), was an Irish guage (1,600 mm (5 ft 3 in)) railway in Ireland. It opened in 1849 as the Cork and Bandon Railway, changed its name to Cork Bandon and South Coast Railway in 1888 and became part of the Great Southern railway in 1924.
The CB&SCR served the south coast of County Cork between Cork city and Bantry. It had a route length of 94 miles (151 km), all of it single track.
Due to economic problems, competition from road traffic and falling passenger numbers, the line closed on 1 April 1961. The tracks were later sold to a scrap dealer and the trackbed sold to local farmers.amazingly, it is still dry inside and in excellent condition.
Construction started in 1845 and was complete in 1849. It has a total length of 400 feet. From the Bandon side,the line ran over the river on a cast iron viaduct which was removed soon after the line closed and at the far side of the tunnel, the line continued over the Brinny river on an impressive stone viaduct which still exists (but is on private land)
The cache site is at the roadside directly above the tunnel at the side of the local road.
I would suggect that you park at the grass triangle on the northern side of the cache site on the road up from Innishannon and walk back down the road looking to the right into the woods until you spot the tell tale telegraph pole amongst the trees. The cache is in a film canister, BYOP.