A survey of booking portal Hotel.info's 6 million users has determined which cities have the cleanest and dirtiest hotel rooms. Tokyo topped the clean list, with a score of 8.93 of 10, with Warsaw coming in second. For dirtiest, Rio de Janeiro was the worst with 7.29 of 10, followed by London at 7.52.
• Hotels: Which Country’s Are Cleanest? | WSJ Japan Realtime