The sauna in Finland is an old phenomenon and its roots are difficult to trace, but its earliest versions are believed to be from 7000 BC. Bath houses were recorded in Europe during the same time period, but Finnish bathing habits were poorly documented for most of history. One of the first written mentions of what is believed to be the sauna customs of the forefathers of the Finns was written by Nestor the Chronicler in 1112. He told of "hot wooden saunas in which naked bathers beat themselves with branches and finally pour cold water over themselves".