Black Law, Upper Cairn and Rumbling Well Loop

This 17 km (10.6 mi) loop is a gentle but exposed moorland outing in the Pentland Hills, linking Black Law, Upper Cairn and Rumbling Well on broad upland ground with only around 200 m (about 656 ft) of total ascent, so it is best thought of as an easy walk in terms of gradient rather than shelter or underfoot comfort. The route is associated with Garvald, a tiny hamlet on the South Lanarkshire–Scottish Borders side of the Pentlands, and the most useful landmark for the start is Garvald near West Linton/Dunsyre, rather than a formal trailhead with major facilities. Black Law itself lies near Garvald and Dunsyre, and the nearby Covenanters’ Grave on Black Law is a well-known landmark in the area. (mapcarta.com)

Expect a walk of long horizons, grassy and peaty tracks, old drove-road character, and a sense of crossing from one drainage basin to another. The terrain is mostly rolling rather than steep, with wide views over the Pentlands and the surrounding Borders uplands when visibility is good. Although the elevation gain is modest for the distance, the route can feel longer than the numbers suggest if the ground is wet, because sections of these hills are known for boggy, squelchy going and faint paths. (geograph.org.uk)

What the route feels like

From the Garvald side, the walk typically begins on quieter farm access tracks and rights of way before moving onto open moor. The first few kilometres are usually the easiest underfoot, giving you time to settle into the day before the route reaches rougher upland ground. Around Black Law the path can become sketchy in places, though waymark posts have been noted on the moorland approaches, which helps on featureless stretches. This is a route where visibility matters: in mist, broad ridges and shallow undulations can make navigation less obvious than the map suggests, so having the route downloaded in HiiKER is sensible. (ronaquirkybirdgardener.blogspot.com)

Black Law is not a dramatic peak in the jagged-mountain sense, but it is a rewarding high point on a rounded upland ridge. The summit area is broad and open, with a distinctly moorland character rather than a sharply defined top. Depending on the exact line of the loop, you may pass close to the Covenanters’ Grave, one of the most historically significant features on the walk. (mapcarta.com)

Upper Cairn and Rumbling Well add interest not through steep climbing but through landscape story. Friends of the Pentlands notes that just beyond Upper Cairn lies Rumbling Well, the source of the Garvald Burn, and that this point marks part of Scotland’s national watershed: water on one side ultimately runs toward the Clyde and the Atlantic, while nearby burns on the other side run toward the Tweed and the North Sea. That makes this section especially satisfying for hikers who enjoy subtle geographical landmarks rather than obvious summit drama. (pentlandfriends.org.uk)

Landmarks, nature and wildlife

The most memorable human landmark is the Covenanters’ Grave on Black Law. The memorial marks the burial place of John Carphin, a Covenanter wounded after the Battle of Rullion Green in 1666. According to the Friends of the Pentlands account, he died near Blackhill and was