Rhapta (Ancient Greek: Ράπτα) was a marketplace said to be on the coast of Southeast Africa, first described in the 1st century CE. Its location has not yet been firmly identified, although there are a number of plausible candidate sites. The ancient Periplus of the Erythraean Sea described Rhapta as "the last marketplace of Azania," two days' travel south of the Menouthias islands (Chapter 16).
According to Claudius Ptolemy, Diogenes, a merchant in the Indian trade, was blown off course from his usual route from India, and after travelling 25 days south along the coast of Africa arrived at Rhapta, located where the river of the same name enters the Indian Ocean opposite the island of Menouthias. Diogenes further describes this river as having its source near the Mountains of the Moon, near the swamp whence the Nile was said to also have its source.
Rhapta is also mentioned by the 6th-century author Cosmas Indicopleustes.
G.W.B. Huntingford lists five proposed locations for Rhapta:
Huntingford dismisses the first two as being too close to Zanzibar and Pemba islands (which he identifies with Menouthis, and follows the author of the Periplus in locating Menouthis north of Rhapta). He observes that there is no river at Msasani, and thus concludes Kisuyu or the Rufiji delta are the most likely candidates. However, J. Innes Miller points out that Roman coins have been found on Pemba; that the Ruvu emerges near the Kilimanjaro and Meru mountains — which confirm the account of Diogenes; and that an old inscription in Semitic characters has been found near the Pangani estuary, which make Pemba a likely candidate for Rhapta.