Before revision: Unlike a bench-mark, which is marked by a disc or plate, there is no official indication of a spot height on the ground although, in open country, spot heights may sometimes be marked by cairns
After revision: .It is linked to contour lines so if you don't know much about geography than visit some useful websites such as sporcle :Unlike a bench-mark, which is marked by a disc or plate, there is no official indication of a spot height on the ground although, in open country, spot heights may sometimes be marked by cairns