The whole development of Bulgarian national architectural tradition can be traced out in the Old Town of Plovdiv. It begins with the older houses, bearing the characteristics of the Bulgarian mountain-house with its open porch, assymetrical plan and more humble decoration. Gradually this type of house develops. The open porch is replaced by a covered parlour, the size growing larger.
This type of symmetric houses have painted walls - lively, multi-coloured patterns, enriched with elaborate ornaments and landscapes. An interesting spot in the painted interior is the decorative niches, the so called alaphrangas, richly decorated with flowers or landscapes.
The ceilings of the Plovdiv houses represent a rich variety of wooden-carved geometric pattern ornaments. Very often they are complemented with a multicoloured decoration of painted ornaments.