Singapore's Changi Airport (SIN) is widely regarded as a destination in itself, and passengers in transit are actively encouraged to explore its world-class facilities. In 2026, the airport consists of four main terminals (T1, T2, T3, and T4) which are connected by a seamless Skytrain and shuttle bus system that operates both "airside" (behind security) and "landside." Transit passengers can visit the famous Butterfly Garden in T3, the Sunflower Garden in T2, or the immersive "Dreamscape" digital garden. A major highlight is Jewel Changi, a massive nature-themed entertainment and retail complex connected to the terminals; while Jewel is technically landside (requiring you to clear immigration), passengers with a layover of at least 5 to 6 hours can easily visit it to see the HSBC Rain Vortex, the world's tallest indoor waterfall. For those with even longer layovers, Changi offers a "Free Singapore Tour" which takes transit passengers on a guided bus trip into the city. Within the secure transit area, you can also find 24-hour movie theaters, swimming pools, and "Snooze Lounges," making it one of the few airports in the world where a long layover is actually considered a highlight of the trip.