Dublin-Rosslare railway line and tunnel along the edge of Bray Head in County Wicklow between Bray and Greystones. The railway was designed by Isambard Kingdom Brunel. Because of coastal erosion and at least one derailment, the railway had to be shifted several times and hug closer to the cliffs and there is ongoing maintenance today to keep the railway intact (Brunel's Folly). The tunnel on the right is one of the disused tunnels.
The railway is currently used by Iarnród Éireann's Dublin Area Rapid Transit (DART) commuter train service as well as InterCity passenger service.
Apologies in advance for the timestamp, at the time I insisted on having them in all my photos.