Lyttelton Rail Tunnel

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 the Lyttelton Line, one of the first railways built by Canterbury Provincial Railways. On completion in 1867 it became the first tunnel in the world to be taken through the side of an extinct volcano, and at 2.6 km (1.6 mi), the longest in the country. Its opening made the Ferrymead Railway, New Zealand's first public railway line, obsolete.

Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).