Inside Changi Singapore Airport Tour. Singapore Changi Airport is regarded as the World's Best Airport and also one of the most luxurious airport. A Butterfly Garden, a Sunflower Garden, Free Movie Screenings, Jewel - a billion dollar shopping complex constructed with the theme of rainforest and world's biggest indoor waterfalls and so on. You can easily spend hours here without getting bored as the activities to be done are so much in numbers. And the best part is most of this things are free to do.