Public baths originated when most people in population centers did not have access to private bathing facilities. Though termed "public", they have often been restricted according to gender, religious affiliation, personal membership, and other criteria. In addition to their hygienic function, public baths have also been social meeting places. They have included saunas, massages, and other relaxation therapies, as are found in contemporary day spas. As the percentage of dwellings containing private bathrooms has increased in some societies, the need for public baths has diminished, and they are now almost exclusively used recreationally. History Public facilities for bathing were constructed, as excavations have provided evidence for, in the 3rd millennium BC, as with the Great Bath, Mohenjo-daro. Ancient Greece In Greece by the sixth century BC men and women washed in basins near places of physical and intellectual exercise. Later gymnasia had indoor basins set overhead, the open maws of marble lions offering showers, and circular pools with tiers of steps for lounging. Bathing was ritualized, and becoming an art, with cleansing sands, hot water, hot air in dark vaulted "vapor baths", a cooling plunge, a rubdown with aromatic oils. Cities all over Ancient Greece honored sites where "young ephebes stood and splashed water over their bodies". Greek public bathing spread to the already rich ancient Egyptian bathing culture, during Ptolemaic rule and ancient Rome. Chinese Bathing culture in Chinese literature can be traced back to the Shang dynasty (1600 – 1046 BCE), where Oracle bone inscriptions describe the people washing hair and body in bath, suggesting people paid attention to personal hygiene. Book of Rites, a work regarding Zhou dynasty (1046 – 256 BCE) ritual, politics, and culture compiled during the Warring States period, describes that people should take a hot shower every five days and wash their hair every three days. It was also considered good manners to take a bath provided by the host before the dinner. In the Han dynasty, bathing became a regular activity every five days. Ancient public bath facilities have been found in ancient Chinese cities, such as the Dongzhouyang archaeological site in Henan Province. Bathrooms were called Bi (), and bathtubs were made of bronze or timber. Bath beans, a powdery soap mixture of ground beans, cloves, eaglewood, flowers, and even powdered jade, was a luxury toiletry in the Han Dynasty; commoners used powdered beans without spices. Luxurious bathhouses built around hot