There is little known for certainty about the early Harappan (Indus River) civilization because much of its artifacts are under water, and its language has not yet been deciphered. However, such artifacts as have been discovered indicate a very advanced and sophisticated society.
Streets appear to have been laid out on a grid, the earliest evidence of such an accomplishment. Private homes had two and three rooms with showers and flush toilets which drained into a central sewer system. Some larger homes had over a dozen rooms. At least one city had a very large pool with dressing rooms for bathers. There is strong evidence that the people of this society sent ships to Mesopotamia for trade which carried ivory, gold, and pearls which were traded for wool, leather and olive oil. The picture is thus of a very affluent and advanced society long before such societies appeared in Western Europe.