Tunnel Beach is a locality 7.5 kilometres (4.7 mi) southwest of the city centre of Dunedin, New Zealand. Located just south of St Clair, Tunnel Beach has sea-carved sandstone cliffs, rock arches and caves. Beyond the beauty of the rugged sandstone cliffs, its claim to fame is the tunnel down to the beach that a local politician, John Cargill, son of Captain William Cargill, had commissioned for his family in the 1870s.
Access to the beach is via a track across private farmland, and is open year round excluding lambing season from August to October. The track was opened in 1983, and is a popular walking track. It descends from 150 metres (490 ft) above sea level at its start, a short distance off Blackhead Road, winding for some 1200 metres to the top of the tunnel close to a natural sea arch. The tunnel descends 72 steps to the beach, and is dimly naturally lit. Note that the path down is steep and can be very slippery following wet weather.