Limeworks in the Moorfoot Hills

There are limework all over the place including one in our lane. But today I went on one of my adventure drives where I pick little roads and just keep on driving and looking around for interesting pictures.
The limeworks are basically kilns built from rubble and earth although this one looks like proper stones were used. They were erected as close as possible to the quarry face. The quarried limestone was broken into small lumps and loaded into the kilm with either coal, wood or peat. The fuel was lit, the kiln sealed over with turf and left to burn for about 10 days or so. The resulting lime was then used in agriculture and in building work. These kilns were called clamp-kilns.
Most were active in the middle of the 19th Century but the earliest date for kilns in Scotland is 1625. I'm guessing these ones are definitely 19th C as the building looks to have quite sophisticated stonework.