There are still many mysteries about the ancient Indus Valley Civilization. But one thing that archaeologists have discovered about these ancient people is that water was very important to them. They of course needed water to drink, which was supplied by rainwater and the Indus. They also built private wells for a handy and safe water supply. Almost all homes had a place to bathe inside, with a tunnel to handle run off wastewater. They built huge public bathing platforms that archaeologists believe were used as places where the women met to wash clothes and socialize. Huge drains were built to handle sewage as well as water runoff for the entire city.
Here comes the mystery: In addition to access to all this water, each Indus town of size had a carefully built huge pool in or near the center of town. The remains of over one thousand ancient towns have been discovered in the Indus Valley. Many had central pools. Each pool was about 40 feet long, 20 feet wide, and about 8 feet deep. Each was built deep enough so that, if it was filled with water, and you were standing on the bottom of the pool, the water would be over your head. On each end, wide steps led down into the pool. A ledge ran along each side, providing a place to stand with your body partly in the water and partly out of the water so that you could breathe. Some archaeologists believe these pools were public water tanks, places to store water. Some guess that the pool was used for religious ceremonies. Some historians have begun to refer to the pool as the great bath. For some reason, almost no historians believe that these pools were simply community swimming pools, which would have been my guess. The truth is, no one knows why huge pools were built in the center of each Indus Valley town of size. It's a history mystery.