There are many prehistoric huts on Dartmoor, and they come in many shapes and sizes. Some of the smaller ones are known as beehive huts and, when built, would have resembled stone igloos, built as they were in a domed shape.
Their exact purpose is unknown, but they were probably too small for habitation, and may well have been used for storage.
This example, on the verge of the East Dart river, is now a ruin, but you can get an appreciation for what it may have looked like in times gone by.