Gardner's Gut is an extensive cave

Cave

A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...

 system in the Waitomo area of New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

. It is located in the Ruakuri Caves & Bush Scenic Reserve, an area that also contains a number of other natural features of note. The reserve is administered by New Zealand's Department of Conservation (DOC). With a length of over 12 km of explored passages, it is New Zealand's 6th largest known cave system, and the largest in the North Island.

Description

The caves making up the Gardner's Gut system are almost all composed of former or still active 'stream caves' (i.e. tunnels washed out of the limestone by water action). It is a very well known cave in New Zealand, and probably one of the most visited 'amateur' caves in the country (as opposed to tourist caves providing guided tours, like nearby Waitomo Cave

Waitomo Caves

The Waitomo Caves are a village and cave system forming a major tourist attraction in the southern Waikato region of the North Island of New Zealand, 12 kilometres northwest of Te Kuiti. The community of Waitomo Caves itself is very small, though the village has many temporary service workers...

). Various caving clubs

Caving

Caving—also occasionally known as spelunking in the United States and potholing in the United Kingdom—is the recreational pastime of exploring wild cave systems...

 from throughout the North Island use it for beginner trips, as it provides a variety of true caving experiences (such as squeeze points, narrow and winding streamways, large underground halls, fascinating formations and bush tramping to get to and from the entrances), yet is easy enough to pass through for any reasonably fit and non-claustrophobic

Claustrophobia

Claustrophobia is the fear of having no escape and being closed in small spaces or rooms...

 person. The normal beginners area of the cave is around the Zweihoehlen-entrance ('Two Holes' in German

German language

German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

) near the river.

Associated with the large number of amateur trips (whether accompanied by professional cavers or not) is a certain level of degradation in the cave. As cave systems are very fragile environments, many parts of Gardner's Gut cave have been damaged by the relatively frequent visits of inexperienced cavers (with, for example, formations broken off, and limestone formations dirtied, which prevents their continuing growth). However, this damage is almost invisible to a casual amateur.

One of the most impressive features of the cave is the 'Birthday Candle', the tallest stalagmite

Stalagmite

A stalagmite is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. This stalagmite formation occurs only under certain pH conditions within the underground cavern. The corresponding formation on...

in the country, being around 6–7 meters high and having a diameter of around 2 meters.