A Pingo is a conical or elongated hill, or even a dome-shaped mound consisting of a layer of soil covering a large core of ice. It occurrs in most areas where permafrost occurs. A pingo contains massive layers of ice formed under hydrostatic pressure .
There are two types of pingos: Open-system pingos and closed-system pingos. Open system pingos have an open conduit that supplies artesian water. Closed-system pingos are formed from a limited water supply trapped by inward freezing of lakes from their boundaries .
Pingos can be up to 70 metres high.