Located on Mushaq island in the northwestern Indus delta, Ratukot was possibly a Sasanian era military fort and customs port. Its primary function would have been to protect the port city of Banbhore that lay 29 kms to the east. From the 20th century onwards, however, the island has largely been swept underwater, with large parts of the island being submerged at high tide. Sea level rise in this part of the delta has also resulted in undermining the fort structure.

The origins of the fort are as yet undetermined, however, archaeologists have discovered pottery sherds dating to the Sassanian or early Islamic period. Historical sources also document Sassanian influence and control of the delta region during the fifth century AD. The Sassanians recognised the coastal region’s importance in the maritime network of the Indian Ocean and often built forts along the coast for protection against pirates.
