Polar Caves Park

Useful Information

Location: I-93 exit 26 at Plymouth, 8 km west on State Route 25.
Navi: 705 Rumney Rte 25, Rumney NH.
Open: 08-MAY to 05-SEP daily 9-17.
06-SEP to OCT daily 9-16:30.
Fee: Adults USD 15, Children (4-10) USD 11, Children (0-3) free.
Groups (10+): Adults USD 11, Children (4-9) USD 8.50.
Classification: SpeleologyPrimary cave, Speleologytalus cave.
Light: LightIncandescent Electric Light System
Guided tours: self guided.
Address: Polar Caves Park, PO Box 826, 705 Rumney Route 25, Plymouth, NH 03264, Tel. +1-603-536-1888, toll free 800-273-1886
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.



Polar Caves were named because of the way they were formed. They are the result of the third continental glacier during the Ice Ages.

During the Ice Ages the temperatures became lower and, probably more important, the amount of rain in the north increased. So there was a lot of snow, which did not melt during summer and formed increasing schields of ice, the glaciers. As ice is not hard as rock, it starts moving under pressure, and with several hundred or even thousand meters high shields of ice, the pressure of their own weight is enough. So the ice of the northern glaciers was kind of flowing south, always melting at the tip.

As long as the amount of new ice was bigger than the amount which melted at the head, the glacier increased, moving south, covering valleys and hills. The continuous movement of ice transported rocks to the south, frozen inside the ice. The melting ice released the rocks and thus produced a wall of debris in front of the glacier, called moraine. The moving glacier pushed the debris like a snow plough.

Like today, the climate changed several times during the Ice Ages and warmer periods with less rain and colder periods with more rain succeeded. During a so called warm period, the glacier became shorter and left the moraine at the position of his longest extend. While it became shorter, it still moved south, but the melting rate was higher than the movement. And still denris was accumulated at the rim.

Polar Cave is a talus cave, which means huge boulders of rock lying on a heap do not really fit, and so there are crevices and cracks between them. They were formed by a shrinking glacier, leaving huge boulders, which came from the north.

Talus caves are rather rare, especially the big ones. At Polar Caves there are three caves big enough to walk through. Their size differs much, narrow passages and bigger rooms are a result of fortuity. One narrow passage is called Lemon Squeeze and is very popular with kids. It is only 40 cm wide.