51 Over time, cairn material slipped off Newgrange and buried the kerbstones, most of which remained totally hidden until excavations began in the 1960s.

Kerbstone 52 at Newgrange

52 The smallest kerbstone is 1.7m long, the largest 4.5m. The diameter of the kerb is between 79m (260ft) and 85m (280ft).

53 Most of the kerbstones are made of grit (grey-wacke) or slate, and according to the archaeologists they were collected rather than quarried.

54 According to archaeologists, the best edges of the kerbstones were placed at the top, while the bottom edges were put into sockets or supported above the ground so that an even top line was formed around the cairn.

55 This line is not horizontal all the way around the mound, however. The line of the kerb follows the contour of the ridge upon which Newgrange sits.

56R.A.S. Macalister attempted to expose the entire kerb in 1928, when he and his workers began digging to the west of the entrance stone and continued until they had revealed 54 stones. At this point, the landowner objected and the work was halted!

57The kerb was constructed in such a way as to curve inwards on either side of the entrance to the passage. This is a common feature which is found in many Irish passage-tombs.

The famous entrance stone at Newgrange, kerbstone 1

58 Despite the often repeated prediction that the highly-decoratede kerbstone 52 marked an entrance to a possible second passage on the northwestern side of Newgrange, no such passage was found or indicated during archaeological work.

59 Some of the kerbstones were decorated before being put into place. Some stones were found with art on their rear, side and on the surface touching the ground. Other kerbstones, such as Kerb 1 and Kerb 52, were decorated in situ.

60 During excavations it was found that some kerbstones were not placed in sockets, but rather on top of a bed or layer of turves.