Singapore

Singapore is the one city that will show you around for free. Changi's Free Singapore Tour takes transit passengers with a layover of 5.5 to 24 hours on a 2.5-hour guided route, with choices that include heritage districts, the Singapore River and Marina Bay Sands, or Sentosa. You report to the booth in the transit area 90 minutes before the start, and checked bags must be through-checked. With longer on the ground and a passport that needs no visa, the MRT takes you to Marina Bay or the hawker centers of Chinatown on your own terms. Some nationalities, including Indian and Pakistani passport holders, need a Singapore visa even to join the tour.