Rhapta was one of the most prosperous cities on the African coast, and one of the last trading posts of the Roman Empire. The ancient Periplus of the Erythraean Sea described Rhapta as “the last marketplace of Azania,” referring to southeastern tropical Africa, but its position remained a mystery. Now, archaeologists may finally be zooming in on its position.

Photo by Alan Sutton.

For years, the lost city of Rhapta has baffled scholars, divers, and archaeologists. Dating to roughly 50 A.D., it was originally documented in Ptolemy’s Geography as Africa’s first metropolis and a major trading hub, with people buying and selling everything from metal weapons to tortoise shells. Rhapta was one of the richest cities of the age, but it simply disappeared and was mostly forgotten for almost 2,000 years. But something changed on a clear day in February 2013.

The usually turbulent waters off the coast of Mafia Island, one of the islets in the Zanzibar archipelago, were strangely still. There was also an unusually low tide, and a strange formation started peaking just above sea level, as reported by a helicopter which was flying nearby. Initially, archaeologists didn’t want to get too excited, but there may well be reason for this after all. Diver Alan Sutton, who documents hidden wreck sites and blue holes online, was flying the helicopter.

He wanted to come back and see the site up close, but couldn’t find it when he tried. After several failed attempts, in March this year, he struck gold. He found walled structures, some still connected to their original fortifications, and pieces of pottery – one of the main indicators of a human settlement.

“What we found was far larger than expected,” he writes. “A series of what appear to be wide foundations ring a large area. Along the entire perimeter created by these foundations, many thousands of square and oblong blocks lie to either side. Some have fallen right off the foundation and others are still leaning against it.”

His findings were confirmed by archaeologist Felix Chami from the University of Dar es Salaam. He is currently dating the artefacts, after confirming sightings of “underwater houses” in the vicinity. Members of nearby communities believe the ruins come from their Portuguese ancestors, but Chami believes that even if this is the case, then the Portuguese likely built on other ruins, possibly the ruins of Rhapta.

“It seems like this is really Rhapta. I feel safe that it’s not German, British or Portuguese. I didn’t see anything that indicates it could be Swahili – no materials. Also, this is the place where Rhapta should be. The Romans say Rhapta is at the delta of a large river that is sailable. The only river that is sailable on the coast of east Africa is the same one [the ruins] sit in – in the bay of Mafia.”

More research is also underway