Documentary sources supplement the scattered visible evidence in the modern landscape. The late eighteenth and early nineteenth centuries produced an unprecedented burst of descriptive writing about the Scottish countryside. One class of pre-improvement agricultural building is still a common feature in the Scottish landscape: dovecotes, or doocots. Doocots epitomise the old feudal order in the countryside. Some traditional buildings survived into the nineteenth century as the homes of smaller farmers and farm workers, or as outbuildings. In east-coast areas pantiles, with their warm red tones, are widely used today for roofing both houses and outbuildings. Because they blend in so well with the landscape they give the impression of being an old-established roofing material. Turf was probably the most common walling material, either used on its own, on top of a stone footing, or laid in alternate courses with field stones.