Metro Cave / Te Ananui Cave, Cave system in Buller District, New Zealand

The Metro / Te Ananui Caves form an 8 km limestone maze in Paparoa National Park, created where Ananui Creek sinks underground. Passages grow younger from west to east. A dry upper level runs from the Triclops entrance to the Ananui Creek entrance, with stalactites, stalagmites and drapery in its caverns.

The karst landscape lay under the sea about 30 million years ago and was later pushed upwards. Over the past 200,000 years, weathering and water dissolved the limestone, shaping both the surface and the underground. The 8 km Metro complex gets younger from west to east, and as the land lifted, upper levels dried out and grew formations while lower levels are still shaped by underground streams.

Te Ananui is the name of the creek that disappears underground and carved the cave passages; the cave is also called Metro Cave. Tours from Charleston include a ride on a bush tram track commissioned in 2002, and the upper levels are walked without ladders or suspended walkways, comparable to a tramping track.

Access involves a short journey from Charleston followed by a ride on a vintage tramway through the bush before walking to the cave entrance. Wear sturdy footwear as the path includes uneven ground and some steps.

Near the Ananui Creek entrance, a partly submerged grotto holds glowworms and cave wētā; visitors can reach it on foot along dry ledges. The 8 km Metro complex also contains bones and shells carbon-dated to between 300 and 25,000 years old.