The Big Bus is a popular sightseeing tour service that operates in various cities around the world. It offers open-top double-decker buses that allow passengers to enjoy panoramic views of famous landmarks and attractions. The tours typically include audio guides that provide information about the history and significance of each site. Passengers can hop on and off the bus at designated stops, giving them the flexibility to explore at their own pace. The Big Bus is a convenient way for tourists to experience a city, as it covers major points of interest and often provides additional services like guided walking tours.