The Lyttelton Rail Tunnel, initially called the Moorhouse Tunnel, links the city of Christchurch with the port of Lyttelton in the Canterbury region of New Zealand’s South Island. It is the country’s oldest operational rail tunnel, and is on one of the first railway lines in the district. On completion in 1867 it became the first tunnel in the world to be taken through the side of an extinct volcano, and at 2.7 km, the longest in the country.