The Camster cairns are probably the best known of all the Neolithic sites in Caithness. The surrounding landscape is rich in remains, including cairns, cists and a stone row. There are two chambered cairns: Camster Round (ND260440) and Camster Long (ND260442). Careful restoration has made them accessible to visitors.
Camster Round was initially explored in the 1850's and 1860's. A long, low passage leads into a magnificently lofty chamber which still has its original corbelled roof largely intact. After further excavation and consolidation in the 20th century, it remains one of the best-preserved Neolithic chambered cairns in northern Scotland. Large vertical slabs divide the chamber into three parts. Excavation uncovered a large amount of human bone, together with animal bone and flint and charcoal.
Excavations of its neighbour, Camster Long in 1860's and the 1970's revealed a complex monument, with several phases of construction. It measures 62 m in length, including the horns at both ends. Two chambers were located at the northern end of the cairn, each seemingly enclosed within an initial round cairn structure. The northern chamber was of a simple polygonal form, with a short passage, while the southern chamber was a more complex tripartite structure with a passage orientated almost due east. It has been suggested that these would have stood as independent structures, before their consolidation within the later long cairn. The simpler polygonal chamber may have been the primary construction on the site. The evidence is not conclusive and the monument may be a single-phase construction. Excavation uncovered bone, pottery and ash.
Evidence for pre-cairn activity beneath the southern end of the long cairn has been recovered. This consisted of a number of burnt areas, varying in size and on the same axis as the later cairn. Dates from the charcoal indicate that this activity occurred in the early centuries of the 4th millennium BC. Finds of pottery and flint debris associated with this burning activity may indicate that early Neolithic communities were using the site for temporary occupation and the manufacture of stone tools.