Alexander Thom Ll/l Class III Survey
Construction: Type A flattened circle the same shape and size as Burnmoor L1/6E. Diameter 107.] ft = 39.4 my. Perimeter 120.4 = 48.2 my. It is remarkable in that 4 astronomical lines came from the geometry of the layout. See survey. It is interesting that the circle at Bummoor (LI /6E) is almost the same size and shape. See second plan where they are superimposed.
Thom's Castle Rigg Plan
view photos at http://www.megalithic.co.uk/article.php?sid=42 or click for higher resolution
Aubrey Burl (Cumberland 8)
This may be one of the earliest stone circles in the British Isles and is certainly one of the most attractive. It is in State care. The ring stands on Chestnut Hill in the centre of the Lake District 1 ^ miles east of Keswick. It was built on a flat stretch of ground at 215 m O.D. The stones are of local metamorphic slate and range from about 1 to 2.3 m in height. The heaviest, set radially to the circumference at the SE, weighs about 16 tons. There were originally about 42 stones in this ring which is noticeably flattened at the NE. Its diameters are about 108 x 98 ft (32.9 x 29.9 m). A wide gap at the exact North, flanked by 2 tall stones, probably indicates an entrance.
Around the circumference are slight traces of a bank. There are also faint remains of a round cairn or barrow 13 ft (4 m) across just NE of the centre (see plan). In 1856 Williams said there were 3 cairns there and that a stone club and a greenstone axe had been found in the ring. An unpolished stone axe, perhaps a Neolithic 'Cumbrian pick' was found in or near the ring in 1875.
At the east, inside the ring, is a rectangular setting of low stones, 22 x 11 ft (6.7 x 3.4 m) which has no obvious parallels in other British stone circles. An excavation there in 1882 discovered a pit at its west end, a metre deep and containing traces of charcoal.
A 0.9 metre high outlying stone stands 2 96 ft (90 m) to the SW of the ring. It may be an outlier that was buried by a farmer, and later dug up because it was damaging ploughs and dumped by the hedge where it was used as a stile. It was finally set upright in its present position about 1913. It has many plough-marks on its face nearer the circle.
Stukeley in 1725 noticed a possible second circle in the field just to the west of the Castle Rigg ring.