The first public bathhouse was mentioned in 1266. In Edo (modern Tokyo), the first "sentō" was established in 1591. The early steam baths were called "iwaburo" ( "rock pools") or "kamaburo" ( "furnace baths"). These were built into natural caves or stone vaults. In "iwaburo" along the coast, the rocks were heated by burning wood, then sea water was poured over the rocks, producing steam. The entrances to these "bath houses" were very small, possibly to slow the escape of the heat and steam. There were no windows, so it was very dark inside and the user constantly coughed or cleared their throats in order to signal to new entrants which seats were already occupied. The darkness could be also used to cover sexual contact. Because there was no gender distinction, these baths came into disrepute. They were finally abolished in 1870 on hygienic and moral grounds. Author John Gallagher says bathing "was segregated in the 1870s as a concession to outraged Western tourists".