Southern Upland Way
The Way is a waymarked route stretching 212 miles (340 km) coast-to-coast across Scotland, from Portpatrick in the extreme south-west of Scotland to Cockburnspath on Scotland's North Sea coast, south of Edinburgh.
It is a much more demanding route than the popular West Highland Way, since it is longer, crosses the grain of the land with much up-and-down, and visits very remote areas which lack accommodation and amenities thus forcing the walker to carry plenty of kit and provisions.
Alan Castle has written a useful guide to the Southern Upland Way, described in 13 stages.
Portpatrick to Castle Kennedy
Castle Kennedy to Bargrennan
Bargrennan to St John's Town of Dalry
Dalry to Sanquhar
Sanquhar to Wanlockhead
Wanlockhead to Beattock
Beattock to St Mary's Loch
St Mary's Loch to Traquair
Traquair to Lauder
Lauder to Cockburnspath
Waymerks are small metal tokens concealed in thirteen "kists" hidden along the route as part of a sculpture project. Walkers are invited to keep their eyes peeled for the kists, and may help themselves to a waymerk if they find where they are hidden. Waymerks may be made of lead or copper, or you may be lucky and find one made of silver.
You're often walking all day on forest paths and may not see anyone on this quiet route. Mobile phone coverage, however, is fairly good since you are not among mountains which would block the signal.