Spas have been in existence even longer than the ancient Byzantines which was as early as 330 AD, and have been referred to by the names of hammams, bathhouses, and saunas!

Spas have been in existence even longer than the ancient Byzantines which was as early as 330 AD, and have been referred to by the names of hammams, bathhouses, and saunas! Culturally, they were known to be a leisure activity for the elite, but their health benefits allowed people in need of healing from all sorts of ailments to access their therapeutic benefits

via – The Science Side Of Spas