Harwoods Hole
Harwoods Hole is a cave system located in the northwest of the South Island of New Zealand, in the Abel Tasman National Park. At 183 metres (600 ft), it is New Zealand's deepest vertical shaft. It was first explored in 1958, long after it was discovered. The track to Harwoods Hole is no longer marked or maintained by the Department of Conservation (DOC).
Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).