Legend has it that that the cairns commemorate two Edgar brothers from Wedderlie who were separated at birth but ended up in opposing Scots and Saxon armies and unwittingly fought each other to the death.
Lady John Scott of Spottiswoode excavated the cairns and found a prehistoric cist covered by a flat slab beneath each cairn. During the Second World War they were damaged by tank and artillery fire during military exercises but since then have been rebuilt and are an unmistakable landmark from far and wide and a favourite rest spot on the Southern Upland Way.
Locally the cairns supposedly account for the number of twins in the community around Westruther.
The cairns, built from the ancient Silurian greywacke stones of our hills, are surrounded by heather moorland managed for red grouse, but on the southern slopes sheltered by the nearby spruce forest are magnificent swathes of Blaeberry (Vaccinium myrtillus) in spring a delicate green colour similar to that of newly emerged beech leaves.
Blaeberry is a deciduous sub-shrub well-known for its tasty purple berries in late summer, but less conspicuous are the delicate flowers, hanging down like miniature pink Chinese lanterns.
A recent visit was made to search for the rare Green Hairstreak butterfly whose caterpillar feeds on Blaeberry.
Alas, the day was too cloudy, but the spread of this butterfly in the Borders and recently just into Berwickshire make Twinlaw an ideal habitat. Bumble bees are hardier creatures than butterflies and several of the rare Mountain (or Bilberry) Bumble Bees were feeding on these flowers.
Also in evidence were lots of day-flying Common Heath moths with delicate brown-mottled wings and feathery antennae.
These, along with a large Northern Eggar moth caterpillar feeding on the heather, and a background chorus of Meadow Pipits, Skylarks and Curlews, more than compensated for the lack of Hairstreaks.
Even the dense Spruces of Harecleugh Forest have much of interest, the highlight being numerous colonies of Stag’s-horn Clubmoss creeping along the sides of a track, and in one place a small colony of Alpine Clubmoss.
In 1853 Dr George Johnston in his ‘Botany of the Eastern Borders’ described this as ‘not uncommon’ in the Lammermuirs’. However, it is highly susceptible to muirburn, and after becoming extinct in the county for many years is now making a welcome comeback along just a few tracks in our upland conifer plantations.