Most of us have come across triangulation pillars on the top of hills and mountains and know that, while they have something to do with the detailed mapping of Britain by the Ordnance Survey, their main use is for standing on, leaning against, sheltering behind or, if you're very daring, doing yoga on.
There are four on Western Ardnamurchan out of the total of over 6,000 in the UK. They stand on the tops of Meall nan Con, above, on....
....the summit of the highest hill, Ben Hiant, on....
.....Druim na Claise between Ormsaigbeg and the lighthouse, and on Beinn Bhreac (below).
Only one, that on Meall nan Con, is of the standard design, being square in cross-section. The ones on Ben Hiant, Druim na Claise and Beinn Bhreac are cylindrical. These are much more unusual, are called Vanessas, and are only found in Scotland.
Vanessas were designed to be smaller and lighter than the standard 'Hotine' model and, therefore, easier to instal on the more remote tops. Even so, the effort to carry all the concrete and parts to the summits of these hills must have been considerable.
For more about the history of these pillars, there's a BBC page here.