Grey Cairns of Camster

4500–3000 BC: The Grey Cairns of Camster are two large Neolithic chambered cairns in Caithness, Scotland, about 14 km south of Watten and 8 km north of Lybster [1]. Among Scotland's oldest structures at roughly 5,000 years old, they showcase complex Neolithic architecture with central burial chambers entered through narrow passages [1][2]. The cairns were excavated and restored by Historic Environment Scotland in the late 20th century and remain open to the public [2].