Long barrows are burial grounds from the early neolithic period. They were built approx. 5-6000 years ago. A long barrow consists of one or more burial chambers covered by a mound.
The mound did not get it's final length at one time. New burial chambers were added next to the mound in continuation of the earlier ones. Everytime, the mound was extended past the new chambers. Large fieldstones are often seen placed around the edge of the mounds. They are remains of a barrow circle.