After Kelleth, remains can be found of small scale industry, making use of the local limestone. These 'rock ovens' were used for baking limestone to convert it into various lime products eg. mortar for buildings, lime for 'sweetening' fields, or for chemical processes. Quite why there are three kilns here is an interesting question. Maybe to expand production it was easier just to build another kiln. They are all in a dilapidated state, especially the first one. The arches of the 'draw holes' are all still intact, but the top courses of stone look to have been taken for reuse, and some parts have collapsed.
These would probably have been 'local' kilns with most of their output used for local needs, with any excess carted to local towns. The coming of the railway may explain the three kilns as the trains brought markets much nearer. This is definitely the case for a pair of much larger 'industrial' lime kilns built in Smardalegill, further east. The railway brought in coal for fuel and 'exported' the finished lime to Darlington and Barrow for steel production. Production in Smardale was limited, however, because the high quality limestone was soon exhausted. There are a lot of sandy/muddy layers associated with the limestone in this area, together with pure layers of sandstone.
Keep your eyes peeled as the kilns aren't too easy to spot if you whiz past. You can either park near the cache, or use a handy 'layby' at the waypoint given below, which is safer. This section of the road gives great views south into the heart of the Howgills. The obvious 'lump' at the end of Bowderdale is Yarlside.
Time for a walk at No.4