Ancient Rome developed a network of aqueducts to supply water to all large towns and population centers and had indoor plumbing, with pipes that terminated in homes and at public wells and fountains. The Roman public baths were called thermae. The thermae were not simply baths, but important public works that provided facilities for many kinds of physical exercise and ablutions, with cold, warm, and hot baths, rooms for instruction and debate, and usually one Greek and one Latin library. They were provided for the public by a benefactor, usually the Emperor. Other empires of the time didn't show such an affinity for public works, but this Roman practice spread their culture to places where there may have been more resistance to foreign mores. Unusually for the time, the thermae were not class-stratified, being available to all for no charge or a small fee. With the fall of the Roman Empire, the aqueduct system fell into disrepair and disuse. But even before that, during the Christianization of the Empire, changing ideas about public morals led the baths into disfavor.