Elevation

Being able to walk up a volcano on the way home is one of the reasons why I love living in Edinburgh.

Triangulation point at the summit of Arthur's Seat.

It's amazing how many peaks across the United Kingdom have had these large lumps of concrete hauled up them.

I understand that the whole thing began in 1935 to allow Ordnance Survey to map the whole country with an unrivaled level of precision.

The result of which means that Munro baggers across Scotland are met with the same goal on so many peaks.

All of these are now redundant due to satellite GPS which is far more accurate.