Font Size

100% 150% 200%

Background Colour

Default Contrast
Close Reset


Date 2010

Event ID 885946

Category Documentary Reference

Type Reference


NB 1640 3425 The megaliths of Callanish VIII are located at the top of a 12.5m cliff on almost level ground. The hill rises behind to 32.5m. The five megaliths (four still erect and one felled in prehistoric times) are not set in any circular shape or even a semi-circle. The site is a combination of two or more astronomical settings. The W part of the site lies over a gully. The gully was filled in c1800 BC with stones and redeposited till, bounded on the S by a retaining wall (DES 1988, 32) forming a level platform/terrace with a cobbled surface some 16.5m E–W x 4.5m N–S. The E part of the site has conventional megaliths with socket holes. There are other standing stones in the vicinity as well as burial cairns and rock carvings (DES 1987, 61; 1999, 94). Three pairs Labelled drawing of Callanish VIII seen from N of glacial erratics/boulders/stones (not megaliths held in socket holes with packing stones) are associated with site Vlll and should be regarded as outliers, foresights for solar and lunar events, and as integral parts of site Vlll. B Somerville 1912, 45–46 drew attention to a boulder which he claimed to act as a ‘May Day’ (Beltane) sunrise marker from Callanish Vlll. There are two boulders at NB 17745 34895. The N boulder is 1.05 x 1.45 x 0.65m. The S boulder is 1.05 x 1.35 x 0.75m. They are more like glacial erratics on thinly covered rock than ‘proper’ megaliths. They lie diagonally to the line of sight. They are 1.53km away, at an elevation of 1.5333° and at azimuths of 60.0333 and 60.2833°. They have an average declination of +16.1259°.

The W stone is set at the edge of the infill and a platform built over the gully. Its large packing stones are also part of the retaining wall. Its S face has a putative cup mark, 55mm diameter and its attitude indicates the ‘May Day’ sunrise boulders. For a person standing at the western part of the platform, the gap between the W stone and the J stone defined the junction between the near and far hillsides (27m and 1.53km) and the two ‘May Day’ boulders.

We propose that part of site Vlll was a Beltane/Lammas solar observatory with the platform and some megaliths at site Vlll constructed at the limit of observation for a particular solar event. If the retaining wall and platform had not been constructed in the gully in the rocky clifftop, an observer would have been too low to see that particular sunrise at all. A person could have seen the sunrise behind the boulders from the E part of the site, but it would have been in an open stretch of horizon, not the horizon junction position. Somerville also reported that due S was marked by a boulder on the skyline. There are two boulders (not ‘proper’ megaliths) on the thinly covered rock of Cnoc Buaile Folaich at NB 1635 3346, 0.79/0.80km from site Vlll.

The E boulder (Somerville’s) is 0.75 x 0.70 x 0.55m. The W boulder is 1.20 x 0.45 x 0.40m. They are 7.4m apart diagonally to the line of sight. The viewing stances which would indicate due S, were on the crest of rock at the top of the cliff, and 15m away between the two megaliths N and J. Ron realised that by going northwards uphill from stones N and J only 10m, a further horizon could be seen with two more boulders on the skyline, directly above the other pair. These have become known colloquially as ‘Ron’s boulders’. They lie on the bare rock of Ben Fuailaval at NB 1620 3126,

2.98km from site Vlll. The E boulder is a rounded glacial erratic about 1.1 x 0.8 x 0.8m. The W boulder is more angular in shape and is about 1.15 x 0.7 x 1.1m. They are about 23.53m apart diagonally to the line of sight. 51m uphill from the J and N stones there is a steeper rocky area which Ron believed to be the top of the N–S viewing line, and from where the S extreme moon at its lowest path always appeared. The S extreme moon could have been predicted by monitoring how moon passes related to the two pairs of S boulders, seen from stances along the 66m N–S viewing line. Perturbations and the daily declination deficit would have complicated observations and predictions. A similar system exists at Callanish l for predicting the S extreme moon.

Curtis MR and GR Curtis. Unpublished material 2006

Somerville, BH. Prehistoric Monuments in the Outer Hebrides, and their astronomical significance in Journal of the Royal Antropological Institute, 42, 1912, 45–46

Archive: A full detailed version of this report is held on the RCAHMS

database (Canmore ID 4112)

People and Organisations