Description

Bryn Celli Ddu – the Mound in the Dark Grove – is probably the best known prehistoric monument on Anglesey. First explored seriously in 1865, the tomb was thoroughly excavated in 1928-29. The excavations revealed that the monument seems to have begun in the later Neolithic as a ‘henge’ or ritual enclosure. It consisted of a bank (now lost) around an inner ditch, which enclosed a circle of upright stones. The ditch originally measured 21m in diameter and was 5.2m wide and 1.8m deep. Its outer edge can still be seen and several stones from the inner stone circle also survive. At a later date, towards the end of the Neolithic, the henge made way for a passage grave, a type of burial monument. A new stone burial chamber was constructed within the henge and was covered by a substantial mound that extended into the ditch, obscuring the earlier stone circle. The present mound is only a partial reconstruction, but the original kerb can be seen within the henge ditch.

The entrance into the burial chamber is on the north-east and consists of a narrow dry-stone wall passage. The passage is divided by two tall portal stones into an outer stretch, 3m long which was probably never roofed, and an inner section 4.9m long and 1.5m high. The outer passage was blocked when the tomb ceased to be used. A low shelf can be seen along the north wall of the inner passage. The passage leads to a polygonal stone chamber 2.4m wide, roofed by two capstones. Inside the chamber stands a neatly dressed free-standing pillar almost circular in shape. One of the stones on the south wall of the chamber has a spiral design carved on it. Human bones, both burnt and unburnt were found in the chamber and passage of the tomb. The absence of pottery makes it difficult to date the tomb closely.

Outside the tomb, to the rear, a large stone was discovered with a wavy, spiral pattern carved into it. The curvilinear style of decoration on the stone has parallels on tombs elsewhere, especially in Brittany. A cast of this has been set up to indicate its presumed original position.

The monument is of national importance for its potential to enhance our knowledge of prehistoric burial and ritual practices. The burial chamber is an important relic of a prehistoric funerary and ritual landscape. It retains significant archaeological potential and there is a strong probability of the presence of burial, ritual or structural evidence. The monument's importance is further enhanced by its rare rock art.

The scheduled area comprises the remains described and an area around them within which related evidence may be expected to survive.

Source: Cadw