DODOMA (Web Desk) – A diver reportedly discovered an “ancient sunken city” off Tanzania’s Mafia island last month. The lost city is believed to be 2000 years old.

According to reports, diver Allen Sutten found the lost city after spotting the ruins from a helicopter and decided to work out what it was. He had no idea how lucky he was, as the ruins are only visible when the spring tide is unusually low.

After Allan first spotted the ruins from a helicopter, it took him almost 3 years to pinpoint their exact location. On March 21, this year, he finally discovered the ruins that are likely to reshape the way we think about African history.

According to archaeologist Felix Chami, the ruins are of Rhapta civilization judging by the construction techniques, ceramics and location, which all neatly fit in with early descriptions of the time.

Here’s a short documentary on the discovery: