Gray Line is the largest provider of sightseeing tours on the planet. For more than 100 years, Gray Line has been at the center of creating and operating the best traveler experiences in the worldÍs most sought after sightseeing destinations. With thousands of tours and experiences in more than 700 locations, spanning six continents, Gray Line is also the largest direct supplier of destination services to online travel sellers, wholesalers and travel agents. Founded in 1910, Gray Line has grown into the most well-known consumer brand in sightseeing tours. Its global network of elite providers operates day tours, airport transfers, hop-on hop-off tours, multi-day packages, walking tours and other specialized destination services.