City Sightseeing's open top double decker Hop On Hop Off bus tours are familiar to over 5.5 million passengers Worldwide. In only 11 years we have become the number one open top bus operator with over 90 town and city tours Worldwide. Over 30 of these tours operate in the UK with a further 40+ in mainland Europe. In total City Sightseeing operates in 30 countries and on 5 continents.