After mapping streets, and many public parks, resorts, canals, rivers, islands; Google's Street View service has now turned its attention to some indoor locations.   

Over the recent past, Internet search giant Google has added sixteen international airports as well as more than fifty train and subway stations to its widely popular Street View service.

The majority of the recently mapped indoor locations are from America, Canada and Europe. In the UK, the Gatwick Airport, London's national train station, Manchester, Liverpool, and Leeds' train stations are among the 17 indoor sites that have already been mapped by the service.

Announcing the development, Google said mapping of indoor locations like airports and train stations would be very helpful to tourists in unknown locations.

Ulf Spitzer, program manager at Google Street View, wrote in a blog post, "Now you can visit the check-in counter of your airline in Madrid, map out the way from baggage claim to the bus at Tokyo International Airport and check out where to pick up your rental car at Eindhoven Airport."

Google's Street View service is not only the world's most popular mapping service but also one of most controversial ones. In May this year, British information watchdog ICO threatened Google with criminal proceedings for failing to delete people's personal information that its Street View cars gathered from public Wi-Fi networks.