Lothal

"The most remarkable structure, alongside the town’s eastern side, is a 217-m-long, 36-m-wide basin. (Its proportions, incidentally, are almost exactly in the ratio of 6:1.) If we consider that its 1.5 to 1.8 m-thick walls were made of millions of carefully adjusted baked bricks, we will have an idea of the energy and resources deployed on its construction. No other Harappan site has so far come up with such a huge water structure (as long as two-and-a-half football fields!). In view of stone anchors and marine shells found in it, S.R. Rao, the excavator, identified it as a tidal dockyard: at high tide, boats sailing up the Gulf of Cambay would have easily pushed on upstream the Bhogavo before berthing at Lothal’s basin."

"India has given to the world the earliest dockyard known to humanity."

"Lothal was probably the most important port after Dvarka drowned. Both were gateways to Sarasvati lands and dominated maritime trade west and south. At the head of a now diverted River Sabarmati tributary, its 12.2-metre thick walls, protection against floods, enclosed a modest seven hectares (17.29 acres) with habitation outside. The massive 214 metres long, 37 metres wide, 4.5 metres deep dock, originally probably deeper was built with over a million kilndried bricks. Eighteen to twenty metres long and four to six metres wide ships could enter with two passing each other. Away from the main current to avoid siltation, lock gates controlled a channel to the estuary at high tide. Estimated to hold 30 ships of 60 tons, or 60 of 30 tons each, it indicates heavy traffic. Navigational instruments to measure angles of the horizon and stars and stone anchors have also been found. A 3.5 metres long wharf, raised against flooding, connected the dock to a 64-room warehouse, containing merchant seals. Each Indus-Sarasvati merchant had a seal to identify and label imports and exports, authenticating ownership, many found in Mesopotamia indicating their main trade outlet."