Across the Afghan countryside, the most familiar rural building is the qala (Pashto kala): a square or rectangular enclosure of high earthen walls, often with a round tower at each corner. The word comes from the Arabic qalʿa, “fortress”, and survives in many place names, yet most qalas are homes rather than forts. Rooms are built against the inside of the wall, with their doors and windows opening onto a shared central courtyard, so one qala can shelter several generations of a single family.
Builders traditionally raise the walls in pakhsa, layered cob, or in sun-dried mud brick (khesht-e kham), sometimes on a stone footing. Scholars note that walled courtyard compounds with corner towers have a very long history here: buildings of this plan dating to the 2nd millennium BCE have been excavated in northern Afghanistan. Large family qalas are most common in the south-east, while in many newer ones the towers have shrunk to decorative features, a sign of how the form adapts as families grow and needs change.