For centuries the great southern ocean and its salt-laden wind have sculpted the sandstone coastline south of Dunedin. The outcome is a line of high cliffs, arches and headlands that provide endless vantage points for breathtaking views as the ocean continues its relentless artistry.Tunnel Beach, just two kilometres south of Dunedin, draws its name from a passage that was hand carved in the 1870s through a rock promontory to allow access to a secluded and sheltered beach at the base of the cliffs.The Tunnel Beach Walkway is an easy one hour return walk - although there's obviously a bit of a climb involved. The walk is at its best around low tide. As well as the spectacular long distance scenery, there are close-to-hand discoveries to be made within the rock along the way. Careful examination will reveal shell fragments and possibly a fossil, such as a brachiopod shell or echinoderm (sea urchin), or even bones of an extinct whale. At the top of the tunnel and on the promontories, the rock supports tenacious plant species, such as spleenwort, that happily exist in the absence of soil.Tunnel Beach is located off the Dunedin to Brighton coastal road. The track starts from the car park at the seaward end of Green Island Bush Road, off Blackhead Road. Public transport is available. The walkway is closed for lambing from 1st of Aug- 31 Oct.