58.1975°N, 6.7456°W.
The Callanish Standing Stones rise on a low ridge above East Loch Roag on the Isle of Lewis in the Outer Hebrides of Scotland, the principal monument of a wider complex of at least 19 separate megalithic sites scattered across the surrounding moor. The central ring of 13 Lewisian gneiss monoliths surrounds a 4.8-metre central stone and a small chambered cairn added later, with avenues of paired stones radiating north, south, east, and west to form a rough cruciform plan unique among British circles. Lewisian gneiss is among the oldest rock on the surface of the Earth, dated to roughly three billion years. Construction of the circle is dated to around 2900 to 2600 BCE in the late Neolithic, with the chambered cairn inserted in the early Bronze Age and disturbed burials still recovered from inside. The site was buried under 1.5 metres of peat for millennia and only fully exposed by Sir James Matheson in 1857 after he purchased the island.
Every 18.6 years the southern major lunar standstill brings the moon skimming the southern horizon along the line of the southern row, then setting behind the central monolith of Callanish.