[1] Khamissa is located 40 kilometres (25 mi) southeast of Guelma, the coastal city known as Calama by ancient Roman settlers,[2] and 32 kilometres (20 mi) northwest of Souk Ahras, known as Thagaste by ancient Berbers and Romans.

[3] Originally the site was a primary settlement of an indigenous Berber tribe of Numidia.

[1] Khamissa became the seat of a bishopric, with a rectangular basilica having walls covered with marble constructed in the 2nd century.

Khamissa has a well preserved Roman theatre (built 2nd or 3rd century), considered one of the most beautiful and best-preserved in North Africa.

Archaeological excavations, conducted from 1900 to 1922, cleared only one part of the town site.