Full text article available at http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=209&doi=10.11648/j.ija.20210901.14The island of Bwejuu is one of the islands of the Mafia archipelago on the central coast of Tanzania. It is only 15 km off the Rufiji Delta and its inhabitants carry out cultivation activities on the delta. The Rufiji delta has been considered by several scholars to be the location of the elusive ancient Azania’s metropolis of Rhapta. Past research on the island established that it was of the 16th–18th centuries post-Swahili civilization. This research has verified that finding although underwater work on the south-east part discovered pottery attributed to ancient transoceanic activities, possibly arriving from either the Mediterranean region or probably Oman or Indian regions. Sites with trade remains from those regions have been discovered on the Delta and Mafia archipelago. Also, an underwater site with wall-like structures believed to be remains of a long- submerged ancient settlement has recently been found in the northwestern waters of Mafia Island. The site has drawn attention of some archaeologists who believe it could be the long-lost metropolis of Rhapta. The new findings from Bwejuu Island may suggest that there are several trading sites in the region of the Mafia archipelago and the Rufiji Delta as outskirts of a large settlement which could be Rhapta. This study collected data through archaeological surveys and test excavations. Data analysis involved pottery attribute analysis and metric dating by thermoluminescence method.