Archaeologists discovered two 4000-year-old cities, 400 miles apart, along the banks of the Indus River in Pakistan. These expertly constructed cities were parts of an advanced civilization comparable to ancient Mesopotamia and Egypt. We don't know what the ancient people of the Indus River Valley called themselves. Archaeologists named the cities Mohenjo-Daro, which means “hill of the dead,” and Harappa, after a nearby city.

The people of Mohenjo-Daro and Harappa lived in sturdy brick houses that had as many as three floors. The houses had bathrooms that were connected to sewers. Their elaborate drainage system was centuries ahead of their time. Archaeologists have found the remains of fine jewelry, including stones from far away places. This shows that the people of the Indus Valley civilization valued art and traded with other cultures.

We don't know what happened to the Indus River Valley civilization. It seems to have been abandoned about 1700 BC . It is possible that a great flood weakened the civilization. The moving tectonic plates that created the Himalayas may have caused a devastating earthquake. It is also possible that the people may have been defeated by another culture.

What we know about the Indus civilization is evolving. Archaeologists are continuing to find new artifacts. In time, we may learn how this amazing civilization developed, how they learned to create an advanced ancient civilization, and why they suddenly disappeared.