Timgad (Arabic: تيمقاد; called Thamugas or Thamugadi in old Berber) was a Roman city in the Aurès Mountains of Algeria. It was founded by the Emperor Trajan around AD 100. The full name of the city was Colonia Marciana Ulpia Traiana Thamugadi. Trajan named the city in commemoration of his mother Marcia, eldest sister Ulpia Marciana, and father Marcus Ulpius Traianus.
Located in modern-day Algeria, about 35 km east of the city of Batna, the ruins are noteworthy for representing one of the best extant examples of the grid plan as used in Roman town planning. Timgad was inscribed as a World Heritage Site by UNESCO in 1982.