Isbister, more popularly known as the Tomb of the Eagles (after the
remains of white-tailed eagles found within), is perched above a sheer cliff
on the island of South Ronaldsay. The entrance faces the sea: a breathtaking
aspect, especially on a stormy day.
Isbister appears to be a stalled cairn at first sight, but actually has
three side cells leading off the main chamber, similar to Maes
Howe sites. The site was excavated by its owner, a local farmer, Mr
Ronald Simison. The north-end compartment and one of the side cells had
been cleared before his excavations, but the remainder of the site yielded
many human and animal remains, as well as Unstan pottery, bone and shell
beads, stone implements, and flints.
The human bones in the tomb represented
340 people; the skeletons were disarticulated and incomplete, the bones bleached and weathered, making it very probable that the bodies had
been laid out on mortuary platforms, exposed to the elements and birds of
prey, before interment.
Study of the human bones indicate that everyone had a right to burial
in the tomb, rather than only segments of the community. Very few people
lived beyond the age of about 25 years, and the few people who lived as long
as 50 years would have had a vital role in maintaining traditions and expertise.
Physically, Isbister people were smaller than today's population: men averaged
1.7 m (5 ft 7 in) and women averaged 1.6 m (5 ft 3.5 in), but they were
very muscular. Many factors were probably involved in this early mortality
rate, but one of them was certainly osteoarthritis, a degenerative disease
of the spine: at least 47% of the population suffered from it.
The tomb contained at least 10 carcasses of white-tailed
sea eagle (Haliaeetus albicilla). Like dog skulls at Cuween
they may have been a totem or emblem of the group which built the tomb.