City Sightseeing is a World's largest excursion sightseeing bus tour operator. It provides tour bus services in more than a hundred cities around the world. The tours are operated by well-recognisable red open top double-decker buses.
The tourist attraction buses travel near major landmarks, while a prerecorded or live commentary in multiple languages is provided through small headphones to passengers. Tourists may leave and board the company buses within their ticket's time limit at special bus stops on a circular route. This is called hop-on-hop-off. In large cities buses go on more than one route. On some routes buses leave the city for suburban sights (such as from Sintra to Cabo da Roca). In some cities (such as New York City) buses operate even at night. In some cities (such as Prague, Moscow, Saint Petersburg) some variants of the ride include travelling by boat. The United Kingdom, Italy and Spain are the countries with the largest number of cities with City Sightseeing service.
Tickets are issued for either one or two day rides, and are purchased at tourist attractions or online. Tickets and discount offers are transferable between the worldwide tours. In some cities, rides by City Sightseeing are included in the city's guest card. A free map of the route for each city is offered as guide and advertisement as well as headphones are free for users. In 2011, nearly 13 million tourists took City Sightseeing tours