The Isbister stalled cairn – South Ronaldsay’s ‘Tomb of the Eagles’

Saturday, March 1, 2025 (4:24 PM)

“Isbister, classified for convenience as a stalled chamber, is an exceptional tomb not least for the extraordinary quantity of human bone it contained, and which has been very fully studied.”

Audrey Henshall. The Prehistory of Orkney (1985)

The Isbister stalled cairn, South Ronaldsay. (📷 Tomb of the Eagles)

By Sigurd Towrie

The Isbister stalled cairn, better known today as the Tomb of the Eagles, sits near a cliff edge at the south-eastern end of the island of South Ronaldsay.

The earliest radiocarbon dates from the human bone suggest it was in use from around 3300BC [1] [1b]. Partially cut into rock, the Isbister cairn, like Unstan, is considered to be a hybrid, containing the stalled compartments of the Orkney-Cromarty cairns and three side cells of the Maeshowe-type.

The 8.2-metre-long, rectangular chamber was divided into five compartments – two end chambers and three, unpaved stalled compartments – by four pairs of divisional orthostats projecting from the walls. These, however, differed from the “typical” stalled cairns in that the two central orthostatic pairs protruded a mere 10-15cm from the walls.

The result was “that the main part of the chamber is, in effect, a narrow rectangular space, its divisions indicated by slabs which hardly project.” [2]

Typical of the Orkney-Cromarty stalled cairn “template”, the two end chambers, measuring c1.8 wide by about 1.2m deep, featured massive back-slabs against the rear walls. They were also “shelved” – although only the southern example survived – c.1.2m above the paved chamber floors. The end chambers were separated from the central area by low, stone slabs running across their entrances.

Access was by a passage in the centre of eastern side, the entrance of which had been destroyed by erosion. The surviving passage section is c.4m long, 70cm wide and 85cm high.

The three side cells – two in the western wall and one in the north-eastern wall – were entered by short, narrow and low passages (c.0.7m long, 0.55m wide and 0.7m high). The cells themselves were small and irregular (c.1.5-2m wide and c.1m deep) and roofed to a height of about 1m.

The layout of the Isbister cairn. (Redrawn after Hedges 1983)

Overhead view of the entrance passage and chambers. (📷 AOC Archaeology Group) — Overhead view of the entrance passage and chambers.
(📷 AOC Archaeology Group/AOC Archaeology/South Ronaldsay and Burray Development Trust)

The story of the Isbister cairn’s discovery and excavation is probably as well known as the structure itself.

It was found by the landowner Ronald Simison in 1958, who had noticed what appeared to be a section of exposed walling.

Isbister's stunning, and complete, macehead. (📷 Orkney Museum) — Isbister’s stunning, and complete, macehead. (📷 Orkney Museum)

Clearing away turf and rubble to reach the base, he found a worked stone macehead, two polished stone axes (one fashioned from haematite) and a tiny black, perforated bead. [2b]

Spurred on by his discovery, Simison returned to the mound a few days later, digging down from the top where upright stones were visible through the turf. This revealed a rectangular section – one of the stalled compartments – and part of a side-cell entrance.

Peering into the cell, by the flickering light of a cigarette lighter, Simison saw that its floor was covered with human skulls – his first encounter with the long-dead occupants.

At this point the site was visited by the Inspectorate of Ancient Monuments:

“After drawing and photographing the cairn, chamber, and contents, the various excavations were filled in. Human remains already removed were boxed and brought back to Edinburgh together with all those lying on the exposed floor of the chamber.”

“Bones in the side cell were not further disturbed and stones were placed across the entrance to it to prevent back-fill from entering and causing damage.” [3]

3d model of the pestle macehead found outside the Isbister cairn. (📷 Hugo Anderson-Whymark)

The sealed cairn was left, pending a thorough archaeological excavation. But this didn’t come. Not due to a lack of interest, but a lack of funds.

After more than 20 years had passed Simison decided to do the job himself:

“It was clear to him that no one else was going to excavate the tomb of Isbister within his lifetime and his solution to this personally unacceptable situation was to turn archaeologist and to do the job himself in as proper a manner as he possibly could.” [4]

He returned to the cairn on several occasions between 1976 and 1982, recovering “the largest and best-preserved single assemblage of Neolithic human bone in the British Isles” [5]

Human remains outside one of the Isbister side cells. (📷 Orkney SMR)

The human remains were considered to be disarticulated and arranged into groups:

“Here and elsewhere in the main area of the chamber there were masses. of disarticulated human bones. They were definitely not skeletons and yet there was a certain order, skulls being ranged along the walls, each with an associated pile of bones.”

“The remaining areas of the tomb were equally surprising. The southern shelved end compartment had human bones piled within it (11) — though skulls were noticeably absent — while the two intact side cells to the west were filled with human skulls.” [6]

We will look at the human remains in more detail in a future post.

In 1987, the structure was received into Guardianship by Orkney Islands Council, who wanted to roof it for public display. This saw a programme of excavation and consolidation to prepare for a concrete roof. [7]

AOC Archaeology Group’s 3d model of the Tomb of the Eagles.

The story of the sea eagles

Among the thousands of disarticulated human bones and fragments were animal remains, most notably that of at least 14 white tailed sea eagles [8] and perhaps as many as 23 [4]. At the time they were interpreted as deliberate deposits, made throughout the life of the chamber, and their presence earned Isbister the title “Tomb of the Eagles”.

Likening the eagle remains to the dogs found within the Cuween chambered cairn, in Firth, it was proposed the sea eagle was a totem animal for those who placed the dead within Isbister, and perhaps part of an excarnation rite that saw the flesh removed from corpses before interment. [7]

This painted a vivid picture of life (and death) in Neolithic Orkney that persists to this day. However, the notion was dealt a blow in 2006:

“New radiocarbon dates from the Tomb of the Eagles’ eponymous bones suggest the birds were not buried by the tomb’s original builders, scotching the theory that the eagle was their totem animal. Tomb of the Secondary Eagle Deposits, anyone?” [9]

The new dates placed the birds’ death between 2450BC and 2050BC, meaning they were placed in the chamber up to 1,000 years after it was built. This fits with a pattern noted in 2017, suggesting that the deposition of animals in Orkney’s chambered cairns continued long after the inhumation of human remains had ceased. [9b]

Although excarnation was also proposed at the Quanterness chambered cairn in the 1970s, a re-evaluation of its bone assemblage found no evidence for it. Instead it pointed towards complete, fully fleshed bodies being placed within the chamber and left to decay – a process that may have been hastened by deliberate dismemberment. [10]

The Tomb of the Eagles is currently closed to the public, but efforts are under way to raise money to allow it to reopen.

The cliffside location of the Isbister cairn. (📷 Tomb of the Eagles)

Notes

[1] As always with chambered cairns we must careful when it comes to basing dates on human remains. They could have been relocated from another cairn, or curated, before deposition.
[1b] Armit, I., Sheridan, A., Reich, D., Cook, G., Tripney, B. and Naysmith, P. (2016) Radiocarbon dates obtained for the Genscot Ancient DNA Project.
[2] Davidson, J. L. & Henshall, A. S. (1989). The Chambered Cairns of Orkney. Edinburgh: Edinburgh University Press.
[2] Although the V-perforated bead was initially said to have been made from jet, analysis by National Museums Scotland in the late 1990s showed it was fashioned from albertite, a material known to outcrop at Dingwall on the north-east Scottish mainland. See Early Bronze Age use of jet and jet-like materials, 22nd century – c 1750 BC. The presence of a probable Bronze Age bead near Neolithic artefacts highlights that Isbister, like other chambered cairns in Orkney, e.g. Cuween and the Taversoe Tuick, continued to be a focus.
[3] Ritchie, P.R. (1961) A chambered cairn at Isbister, South Ronaldshay, Orkney. In Proceedings of the Society of Antiquaries of Scotland (Vol. 92, pp. 25-32).
[4] Hedges, J.W. (1984) Tomb of the Eagles: A Window on Stone Age Tribal Britain.
[5] Lawrence, D. (2006) Neolithic mortuary practice in Orkney. In Proceedings of the Society of Antiquaries of Scotland (Vol. 136, pp. 47-59).
[6] Hedges, J. W. (1985) A Guide to the Isbister Chambered Cairn and Liddle Burnt Mound.
[7] Smith, B. (1990) Isbister, an Orkney Islands Council Guardianship Monument. In Proceedings of the Society of Antiquaries of Scotland (Vol. 119, pp. 55-58).
[8] Hedges, J. (1983) Isbister: a chambered tomb in Orkney. BAR Publishing.
[9] Flight of the eagles. In British Archaeology 86, January/February 2006.
[9b] Bayliss, A., Marshall, P., Richards, C. and Whittle, A. (2017) Islands of history: the Late Neolithic timescape of Orkney. Antiquity, 91(359), 1171-1188.
[10] Crozier, R., Richards, C., Robertson, J. and Challands, A. (2016). Reorienting the Dead of Crossiecrown: Quanterness and Ramberry Head. In Richards C. and Jones, R (eds) The Development of Neolithic House Societies in Orkney. Windgather Press.