Hotel hospitality to travellers have been a feature of the earliest civilizations. In Greco-Roman culture and ancient Persia, hospitals for recuperation and rest were built at thermal baths. Japan's Nishiyama Onsen Keiunkan, founded in 705, was officially recognised by the Guinness World Records as the oldest hotel in the world. During the Middle Ages, various religious orders at monasteries and abbeys would offer accommodation for travellers on the road. The precursor to the modern hotel was the inn of medieval Europe, possibly dating back to the rule of Ancient Rome. These would provide for the needs of travellers, including food and
Onsen found in some onsens with poor sanitation. Revelations of poor sanitary practices at some onsens have led to improved regulation by hot-spring communities to maintain their reputation. There have been reports of infectious disease found in hot bodies of water worldwide, such as various "Naegleria" species. While studies have found the presence of "Naegleria" in hot spring waters, the worrisome "Naegleria fowleri" amoeba has not been identified. Nevertheless, fewer than five cases have been seen historically in Japan, although not conclusively linked to onsen exposure. Many onsens display notices reminding anyone with open cuts, sores, or lesions not to bathe.