The Wirral line is one of two commuter rail routes operated by Merseyrail and centred on Merseyside, England, the other being the Northern line. The Wirral line connects Liverpool to the Wirral Peninsula via the Mersey Railway Tunnel, with branches to New Brighton, West Kirby, Chester and Ellesmere Port. Beneath Liverpool, the line follows a clockwise circular route in a single-track tunnel called the Loop, built in the early 1970s.