Cairns are high altitude places that when looted will give you an achievement and some loot.
The cairn is located above Redoubt, in the southeast part of Droughtlands. To climb the mountain get to 8971, 6848 head east, you will cross sideways across a big white face until you drop into a small ravine at 9071, 6899. From there head up to 9160, 6928.
For this Cairn you want to start just south of Meridian in Freemarch. At about (6074, 5363) there is a slight difference in the cliff that lets you jump up and start climbing.
Head generally west and slightly north and you will find yourself at about 5821,5215 where you will have to use those jumping skills again to get up some steep hills/cliff. Now you want to continue climbing north as if you attempt to reach the top of the mountain.
Not far up you will hit an invisible wall. At this point edge yourself left and you should see a patch of green a fair bit down the mountain on the Stonefield side of the border. The invisible border will eventually vanish and you should be able to get down to this patch of grass, perhaps taking some fall damage. Make sure you heal up before continuing, so you won't die and have to corpse run!
Continue heading up and north and be careful not to fall down to your left. Eventually you will come to a small drop and the Cairn is on the area below, some distance away from our NPC friends Stavel Rosso and Sylver Valis.
Climb up the mountain from Timberveil and up to the top. The cairn is located almost right above the defiant porticulum.
Begin at Darkfire Grove and start up the large slope at about 4806,3374. As you travel up you'll pass into Gloamwood. Once you get to the rocks it's quite fiddly to get up them using the little ledges and nooks in rocks. Some parts seem easier on a mount. You also double back on yourself, it's not just a spiral around. The cairn is located on top of the mountain.
Take off to the right from the road from Perspice before you get to Last Hope, around where the mountains on the right side is closest to the road. Just climb up left to the top of the highest mountain and there it is. Very easy to get to.
This Cairn is very easy to get to. When in Stonefield, simply take off the road at about (5348, 5197) and follow the ridge south and up untill you will see some trees on the grass off to the right, the Cairn should be in sight close by.
This Cairn can be a bit tricky to get to, but once you know the way its easy. The easiest way is to run to Camp Fergos and follow the dirt and gras path up the mountain.
Close by is the location of the Spinning Plates, the puzzle of Stonefield.
Fairly hard cairn to travel to. Start from the Twisted Hollow, location (1641, 2090) and travel to location 1613, 2006 then angle over to location 1165, 1710 and then angle walk left and up, the rest of the way is pretty much plain sailing.