The Soldiers' Trenches, Moor of Rannoch
The Soldiers' Trenches on Rannoch Moor are drainage ditches dug by British army soldiers in 1763-64 in an attempt to drain part of the Moor of Rannoch, Fortingall Parish, Perth and Kinross, Scotland. The aim was to produce agriculturally useful land for crops, grazing, etc.
Source: Wikipedia — The Soldiers' Trenches, Moor of Rannoch (CC BY-SA 4.0)