Mausoleum B, almost 100 meters northwest of the Cardo, provides an unusual insight into Punic Sabratha, even though what you see is a rebuilding of the original. The mausoleum is almost 24 meters tall and stands on the site of an underground funerary chamber dating from the second century B.C. It has a triangular foundation, concave façades and a little pyramidal structure on the top.

The decorations (originals of which are in the Punic Museum) illustrate Bes and Hercules, who are thought to have been the protectors of the crypt, as well as lions. The mausoleum was dismantled by the Byzantines, who used the materials to construct their wall around the town in the sixth century.