Caves in the Nelson area
From Takaka Hill, south to the Arthur range and to Mt Owen, there are thick beds of marble. This marble has been eroded over time by water to form the country’s longest and deepest caves. The Nelson area is home to the 20 deepest (known) caves in the country.
Mt Owen rises 1875m above sea level and contains the longest cave in New Zealand, Bulmer Cave. Bulmer has over 71kms of explored passage and still going. Trips to the back end of the cave can take three to four days and almost always result in more discoveries. Another cave in the area, Bohemia, is the fifth deepest in New Zealand at 711m, and has over 10km of explored passage. This cave has the largest (known) underground chamber in the country, extending for 800m in length and over 100m in width at the widest point.
Access to the Mt Owen area is via the Owen River or Granity Pass, both of which are energetic walks in especially if carrying a heavy pack. Mt Owen still has many unexplored areas which offer the potential for new discovery and exploration. Expeditions into the region usually employ the use of helicopters to transport equipment, supplies and cavers into to the desired area (heli-caving).
Mt Arthur covers a smaller geographical area than Mt Owen but is more accessible. The two main systems on Mt Arthur are The Ellis Basin System and the Stormy Pot/Nettlebed System. The former recently broke the 1,000m mark (making it on to the list of the world’s one hundred deepest caves; almost all are located in Europe) and has 38km of explored passage. The Nettlebed and Stormy Pot systems were recently connected, resulting in a through-trip of almost 1,200m (in height drop), which is one of the deepest through-trips in the world.
Takaka Hill at the northern end of the marble block is only one hour drive from Nelson. The hill is covered with karst features and offers many adventurous caving trips, most of which require experience and specialised equipment. There are two main resurgences – Riwaka and Gorge Creek. From the top of the hill several caves descend to around 400m. Takaka Hill is famous for it’s impressive Harwood’s Hole, a 176m abseil into Starlight Cave. Takaka Hill is also home to New Zealand’s third longest cave, the Middle Earth/Greenlink System, which is currently over 33kms long. Takaka Hill offers excellent potential for easily accessible new discoveries and it is not uncommon for cavers to stumble across shafts not previously looked at.