Dun Dornaigil is an Iron Age broch in Sutherland in the Scottish Highlands. It is located at grid reference NC 4571 4501 next to the Strathmore River, south of Ben Hope, immediately adjacent to the single track A836 road. Under the care of Historic Scotland, it has limited parking space and an information board for visitors. The interior has been filled and is now inaccessible.
Brochs are Scotland's most impressive prehistoric building structures, dating from approximately 2,300 to 1,900 years old, and are found primarily in northern and western Scotland.
The walls of Dun Dornaigil generally survive from 6ft to 11ft around the circumference of the broch, but above the doorway they rise to 22ft. The construction of brochs, with their double-skinned drystone walls made it possible to build tall yet comparatively lightweight structures. The doorway boasts a massive triangular lintel; though this helps spread the load of the walls, it is not strictly necessary, leading archaeologists to surmise that it was also a statement of the high social status of the inhabitants. Its position on a high terrace overlooking the floodplain and river below gave it a commanding view over the trade route, and makes it a dominant feature in the glen. There are relatively few brochs in the vicinity, which strengthens the supposition that Dun Dornagail's inhabitants were a wealthy family dominating the area.