The mausoleum is attributed to Juba II, the Berber king who governed Mauretania as a Roman client ruler beginning in 25 BC, and his wife Cleopatra Selene II -- the daughter of Cleopatra VII of Egypt and Mark Antony. Their union joined two of the ancient world's most storied lineages: the Numidian royal house and the Ptolemaic dynasty of Egypt. Whether their remains were ever actually interred here is an open question. The tomb was robbed at some unknown point, possibly soon after its construction, and no human remains have been found inside. What survives is the architecture itself -- a monument built for eternity by people whose bodies it could not protect.

The structure is circular with a square base measuring roughly 60 meters on each side, originally rising to about 40 meters and topped with a cone or pyramid. Damage from weather, vandalism, and target practice has reduced the height to between 30 and 32 meters. Sixty Ionic columns once decorated the base, though their capitals have been removed -- likely stolen over the centuries. Inside, two vaulted burial chambers sit separated by a short passage, accessible through a gallery sealed by ingenious stone doors that slide up and down on lever mechanisms. The passage leading to the chambers stretches roughly 150 meters. One chamber measures 43 meters long by 3.3 meters wide and 3.3 meters high. The smaller second chamber sits beside it, a companion space for a companion burial.

The monument carries multiple names reflecting its layered history. In French, it is called the Tombeau de la Chretienne -- "the tomb of the Christian woman" -- because the division lines on the false door form a shape resembling a Christian cross. In Arabic, it is the Kubr-er-Rumia or Kbor er Roumia, which also translates to "tomb of the Christian woman," though through a different linguistic chain: Rum referred to the Eastern Roman Empire, and in North Africa rumi came to mean "Christian." The cross-like pattern on the door almost certainly predates Christianity, an architectural coincidence that has given the monument a misleading but enduring name. Locals and visitors have been seeing a cross in those stone lines for centuries, each generation reading the mark through its own religious framework.

The mausoleum stands within a larger archaeological corridor stretching from Cherchell to Tipaza, where Phoenician, Roman, early Christian, and Byzantine remains crowd the Mediterranean coastline. UNESCO inscribed this group of ruins as a World Heritage Site in 1982, but recognition has not guaranteed preservation. Urban expansion, open sewage drainage, poor maintenance, and persistent vandalism threaten the entire corridor. A 1992 conservation plan was never effectively implemented. UNESCO provided emergency assistance in 2001 and sent experts in 2002, after which the site was added to the List of World Heritage Sites in Danger. The mausoleum that survived the Pasha's demolition crews, the artillery bombardment, and the French Navy's target practice now faces a more diffuse enemy: the slow encroachment of a modern city that has grown up around an ancient king's last monument.