About the model
Research for 3D models of three monuments of the Heart of Neolithic Orkney World Heritage Site, each under 'sites' with its own record, reference point, facts, elements, alignment, phases and debate; sources, plans, OSM features and gaps are shared. Every number is quoted from a fetchable source (checked with bidb.evidence.quote_found); where sources disagree all are kept and the note says so. Quotes from the PSAS PDFs are their OCR text (decimal points print as '-', e.g. '5-7 m' = 5.7 m; '3£ feet' = 3 1/2 ft). 'derived' marks values computed here (grid conversions, OSM distances).
Maeshowe is a late Neolithic chambered cairn (passage grave), the type-site of the Maeshowe group, on Mainland Orkney: a grass-covered mound about 35 m across and 7 m high on a levelled oval platform, inside a wide flat-bottomed ditch and an outer bank. A long low passage from the south-west, lined in its inner part with huge single slabs and with a blocking stone in a recess, leads to a corbelled chamber about 4.6-4.7 m square with a tall standing stone inside a buttress in each corner and three raised side cells. Radiocarbon dates from the ditch put it around 2700 BC (the chamber may be earlier). Norsemen broke in through the roof in the 12th century and carved over 30 runic inscriptions. James Farrer opened it through the roof in 1861; the outer passage was rebuilt and the chamber was re-roofed (HES: a stone roof of the 1860s; Ness of Brodgar: a modern roof of 1910) with a concrete raft over it in the early 20th century. The original Neolithic masonry survives to about 3.8-4 m; everything above is modern. The setting midwinter sun shines along the passage.
A Neolithic henge and stone circle on the Stenness promontory, built c. 3000-2900 cal BC and among the earliest henges in the British Isles. A rock-cut ditch with a single causeway on the north (an outer bank, now rebuilt) encloses a platform about 44 m across with an elliptical ring (about 32 by 30 m) of very thin, tall flagstone slabs, planned as 12 but probably never complete (no stone in hole 12, none likely in 9). Four stones stand: 2, 3 and 5 (5 to 5.7 m) and the short stone 7; stumps 4, 8, 10 and 11 survive; 1 and 6 are empty holes. In the centre is a square stone hearth (2.1 by 1.9 m). In December 1814 a tenant farmer felled stone 5, broke up stone 6 and destroyed the holed Odin Stone outside the circle. In 1906-07 stone 5 was re-erected, stone 7 was found and set up in concrete and a spurious 'dolmen' was built north of the hearth; its capstone was pushed over in 1972 and the 1973-74 excavation (Ritchie) left it lying. The bank was rebuilt in 1985 to its 1851 form. Outliers: the Watch Stone (5.5-5.6 m) by the Brig o' Brodgar and the Barnhouse Stone.
A late Neolithic henge and stone circle on the Ness of Brodgar isthmus between the Lochs of Stenness and Harray, the largest stone circle in Scotland and a near-perfect circle about 104 m across (103.6 m). It stands on a platform inside a rock-cut ditch about 123 m across (originally over 4 m deep and 10 m wide), crossed by two opposed causeways, north-west (about 3-3.4 m wide) and south-east (just over 1 m); no outer bank has been found. The ditch is dated to about 2600-2400 BC; the stones may be earlier or later. Thought to have held 60 stones (the 2008 tomography suggests more, not all at once), of thin flagstone from up to seven quarries in very shallow sockets. Today 27 stand (21 according to the HES Statement of Significance), from 2.1 to 4.7 m high, with stumps and fallen stones; most fallen stones were re-erected after the site came into state care in 1906 (1908 per Ness of Brodgar) and two have since been split by lightning. One stone carries a Norse runic inscription. Barrows (Salt Knowe, Fresh Knowe, Plumcake) and the Comet Stone stand around it; Thom read them as backsights of a lunar observatory, which is not accepted.