Early Indus Valley Routes
Trade routes west would have been via the important city of Mohenjo Daro (about 500km south of Harappa) and then northwest via modern Afghanistan, or south-west inland parallel to the coast via Bampur or the coastal route along the Persian Gulf.
G. Algaze described routes through Syro-Mesopotamia in the Classical Age – numerous east–west routes crossed the high plains reaching Antioch and Damascus, and other (more or less north–south) routes closely followed the Tigris and Euphrates.52 Earlier routes must have followed similar paths.R. Mookerji thought that seaborne trade between India and Babylon must have been carried on since 3000 BCE, citing Indian teak in the ruins of Ur.53 Other contemporary academics considered the maritime trade to have been established later. The Rig-veda, the oldest Indian Vedic Sanskrit text, probably compiled between 1500 and 1000 BCE or earlier, referred to ships and merchants conducting seaborne trade. Mookerji referred to evidence of very large seagoing ships in the Sanskrit and Pali literature. The Indus River to Persian Gulf route navigability was also demonstrated, first by Scylax, sent by the Persian King Darius I in 515 BCE, then by Alexander the Great, whose army sailed down the Indus under the command of Nearchus and then routed via the Gulf to reach Babylon.54