Maeshowe is one of the largest tombs in Orkney;
the mound encasing the tomb is 35m in diameter
and rises to a height of 7.3m.  Surrounding the
mound, at a distance of 15m to 21m is a ditch
up to 14m wide.  The grass mound hides a complex
of passages and chambers built of carefully crafted
slabs of flagstone weighing up to 30 tons.  It is
aligned so that the rear wall of its central chamber,
held up by a bracketed wall, is illuminated
on the winter solstice.