Cashtal yn Ard, near Cornaa in Maughold parish, is a Neolithic chambered tomb dated to around 2000 BC and considered one of the best-preserved megalithic monuments of its kind on the Isle of Man. A west-facing forecourt measuring roughly 6.7 by 5.8 metres leads into five stone chambers arranged eastward along a structure some 39 metres long overall. Excavations by H. J. Fleure and G. J. H. Neely in the 1930s recovered flints, pottery sherds, and around 125 white sea pebbles, though no human bone survived. Set on high ground with extensive views of the surrounding landscape, the tomb's position may have marked a symbolic separation between everyday farmland below and ritual activity conducted above. Its architecture has been compared by researchers to the Giants' Tombs of Sardinia and the Bridestones of Cheshire, linking it to a wider European megalithic tradition.