Somali architecture is the engineering and designing of multiple different construction types such as stone cities, castles, citadels, fortresses, mosques, temples, aqueducts, lighthouses, towers and tombs during the ancient, medieval and early modern periods in Somalia and other regions inhabited by Somalis, as well as the fusion of Somalo-Islamic architecture with Western designs in contemporary times.
Near Bosaso, at the end of the Baladi valley, lies a 2 km to 3 km long earthwork. Local tradition recounts that the massive embankment marks the grave of a community matriarch. It is the largest such structure in the wider Horn region.
On the coastal plain 20 km to Alula's east are found ruins of an ancient monument in a platform style. The structure is formed by a rectangular dry stone wall that is low in height; the space in between is filled with rubble and manually covered with small stones. Relatively large standing stones are also positioned on the edifice's corners. Near the platform are graves, which are outlined in stones. 24 m by 17 m in dimension, the structure is the largest of a string of ancient platform and enclosed platform monuments exclusive to far northeastern Somalia.
Near the ancient northwestern town of Amud, whenever an old site had the prefix Aw in its name (such as the ruins of Aw Bare and Aw Bube), it denoted the final resting place of a local saint. Surveys by A.T. Curle in 1934 on several of these important ruined cities recovered various artefacts, such as pottery and coins, which point to a medieval period of activity at the tail end of the Adal Sultanate's reign. Among these settlements, Aw Barkhadle is surrounded by a number of ancient stelae. Burial sites near Burao likewise feature old stelae.
City walls were established around the coastal cities of Merca, Barawa and Mogadishu to defend the cities against powers such as the Portuguese Empire. During the Adal Age, many of the inland cities such as Amud and Abasa in the northern part of Somalia were built on hills high above sea level with large defensive stone walls enclosing them. The Bardera militants during their struggle with the Geledi Sultanate had their main headquarters in the walled city of Bardera that was reinforced by a large fortress overseeing the Jubba river. In the early 19th century the citadel of Bardera was sacked by Sultan Yusuf Mahamud Ibrahim and the city became a ghost town.