Names attach themselves to a place over time, and Cashtal yn Ard has carried at least three. Before it was the Castle of the Heights, locals knew it as Cashtal y Mucklagh y Vagileragh - the Castle of the Field Pigsty - probably because at some point the wide forecourt of the tomb had been pressed into service as a pen for raising pigs. It has also been called Ballachrink Cairn, after the nearby farm. None of these names mention what archaeologists later realised: that this is among the best-preserved Neolithic monuments in the British Isles, dated to around 2000 BC, and that the symbolic choice of a hilltop may have been the entire point. Everyday life happened in the valleys. Ritual life happened up here, in sight of the sea and a foreign shore.

When the cairn was excavated in the 1930s and again in 1999, no human remains were found. But in 1885 the antiquarian Llewellynn Jewitt had reported the discovery of older bone fragments at the site - pieces of skull with the suture still open, an upper jawbone with teeth regular and sound, the remains of someone young. He also noted pottery: pieces of two different urns, one of black crushed granite, the other red and earthier, and near the east end a smaller urn thickly spangled with mica. Whoever the young person was, they had been laid carefully under the side stones with broken vessels around them. The rest of the bones had been removed long before Jewitt's time, perhaps by earlier antiquarians, perhaps by farmers using the site for other purposes. What remains is the architecture and the absence.

The archaeologists H. J. Fleure and G. J. H. Neely noticed something striking about Cashtal yn Ard when they looked at it alongside other Neolithic tombs across Europe. The structure resembled the Giants' Tombs of Sardinia and the Bridestones in Cheshire, England. Different landscapes, different peoples, but the same instinct: long stone-built passages, a forecourt, chambers for the dead. The Neolithic was a connected world, with shared ideas about death and stone moving from settlement to settlement across improbable distances. A small hill in Maughold, a Mediterranean island and an English county turn out to be speaking the same architectural language. Nothing in the tomb tells us how the connection worked - whether it was migration, trade, or simply the shared logic of how to honour the dead with the materials at hand.

Today the site is open ground, signposted from the small village of Cornaa. There is no roof, no museum, no entry fee. The stones stand where they have stood since people last placed them. You walk up through farmland, you come over the rise, and the tomb is just there - long and low and watchful, with the Lake District a smudge on the horizon if the air is clear. Visitors who come on a windy spring day, when gorse is yellow on the surrounding slopes and the sea below shows white edges on its waves, understand without needing a guidebook why this hill was chosen. The tomb is built for the view. Whoever was laid inside was given the longest possible last look.