Cairn n. : A rounded or conical heap of stones erected by early inhabitants of the British Isles, apparently as a sepulchral monument.

Cairn n. : A pile of stones heaped up as a landmark, or to arrest attention, as in surveying, or in leaving traces of an exploring party, etc.

Example:
Can Cairn Terriers be trained to be friendly with strangers and other dogs?

Taxonomy
cairns, stone, càrn, free encyclopedia, marking system, Hermes, North America, piles, navigation charts, legend, hiking trails, Cairn Terrier, Chambered cairn, Clava cairn, Court cairn, the dead, summit, hikers.

Defination from the web:
cairn (carn in Irish, carnedd in Welsh, càrn in Scots Gaelic) is a manmade pile of stones, often in a conical form. ... A large cairn was built atop a hill next to I-476 in Radnor, Pennsylvania, to symbolize the area's Welsh origins and to beautify the visual ...