The tomb in Rhoslan, also called Cefn Isaf, was built during the Neolithic period, around 4400 – 2900 BC. Constructions of this type were used by early-agricultural communities, as collective burial sites and for perhaps religious ceremonies.
The burial chamber consists of four vertically arranged stones, supporting the largest capstone serving as a ceiling. It is open to the south-east, 2.4 meters along its axis from north-east to south-west and 1.8-meter wide at its north-eastern end. The inner height is 1 meter. The capstone is flat underneath with a maximum thickness of 1 meter, the plan is roughly rectangular with a length of 3.5 and a width of 2.75 meters, with a detached southern corner. The whole was originally covered with a mound of earth or stones, which now completely have dispersed.
Website ancientmonuments.uk, Cefn-Isaf Burial Chamber.
Website megalithic.co.uk, Rhoslan – Chambered Tomb in Wales in Gwynedd.