Indus (Old Indian Sindhu): large river in Pakistan, more or less the eastern limit of the world that the Greeks knew.
The Indus - or Sindhu, "river", as it is called in the ancient Indian languages - is one of the largest rivers in the world. From its source in the Himalayas to its delta near modern Karachi, it is 3190 kilometers long. It passes through Jammu and Kashmir, along the Punjab, and through the southern part of Pakistan that is now known as Sind - of course a rendering of Sindhu. It finally empties itself in the Indian Ocean.
The river becomes really big south of modern Uch, where the river Chenab (a big stream that has already accepted the waters of the Jhelum, Ravi, and Sutlej) empties itself in the Indus. The confluence is called Head of the Punjab. At this point, the stream can be as wide as six kilometer.
All along the river, there is human occupation. Agriculture often takes place on large terraces on the river banks. In fact, the Punjab and Sind are among the most densely populated areas in the world. The ancient Greeks told lots of tall stories about the proverbial wealth of the Punjab and the valley of the Indus. The Greek researcher Herodotus of Halicarnassus, for example, believed that there were gold-digging ants (text).
The Indus carries heavy, sandy sediments from the Himalayas to the the south. From a distance, this looks like concrete, but it is gray sand. The Greek author Philostratus, using an eyewitness from a visitor to the Punjab, writes:
They say that like the Nile, the Indus floods the land and brings down soil over it, and so provides the Indians with land to sow in the manner of the Egyptians.note[Philostratus, Life of Apollonius, 2.19.]
The ancients noted another similarity between the two mighty rivers: crocodiles.