Maeshowe is a grass-covered mound in a field beside Loch Harray, about thirty-five metres across and encircled by a ditch, and inside it is the finest chambered tomb in northern Europe. Built around 2800 BC, it is entered by a long, low passage of huge single slabs, aligned so that around midwinter the setting sun shines straight down it and lights the back wall. The chamber itself is high and square, with corbelled walls that narrow towards the roof and side cells where the bones of the dead were laid. The precision of the masonry, with no mortar, is astonishing, and the stone slabs in the passage weigh several tonnes.
In the twelfth century, Norse crusaders broke in through the roof and sheltered inside from a storm, and they carved runic graffiti on the walls, the largest collection of Viking runes outside Scandinavia. Some are boasts about treasure, some are ordinary names, and one is a crude drawing of a dragon-like beast. The inscriptions link to the Orkneyinga Saga, the history of the earls of Orkney, and a few mention a hoard that, if it was ever there, had gone by the time modern archaeologists arrived in 1861.
Visiting is strictly regulated. You must book a timed ticket in advance through Historic Environment Scotland, and the tour begins at the visitor centre in Stenness, with a short shuttle or walk to the mound. Check the current arrangements, because they have changed in recent years. The passage is low, so you stoop, and the guides tell the story with warmth and humour. Midwinter is the most famous time, but the stone and the lamplight are impressive at any season.
Riding in is simple, on the A965 and B9055 along the loch, and bikes are easily parked at the visitor centre. The roads are quiet and well made, though wind is a constant factor and sheep sometimes wander. Stromness, a little over seven kilometres away, is the nearest place for fuel and a proper lunch, with the pier and the Pier Arts Centre. The bakeries sell the Orkney fudge and bere bannocks, a flat bread made from local barley. Late in the day, as the sun drops over the loch, the mound looks like a swelling of the earth itself.