Having a 16-hour layover at Changi Airport in Singapore provides you with ample time to explore and make the most of your stay. Here are some suggestions for things to do during your layover:

1. Visit Jewel Changi Airport: Jewel is a multi-dimensional entertainment complex located within Changi Airport. It features stunning indoor gardens, the world’s tallest indoor waterfall (Rain Vortex), various dining options, shopping outlets, and unique attractions like the Canopy Park and Sky Nets.
2. Take a City Tour: Changi Airport offers free city tours for passengers with long layovers. These tours typically last a few hours and provide you with an opportunity to see some of Singapore’s key attractions, such as Merlion Park, Marina Bay Sands, and Gardens by the Bay. Check the airport’s website or visit the tour desks for more information and availability.
3. Explore the Gardens: Changi Airport is renowned for its beautifully designed and well-maintained gardens. Take a leisurely stroll through the Butterfly Garden, Orchid Garden, Sunflower Garden, or the Cactus Garden. These serene spaces provide a relaxing environment to unwind during your layover.
4. Relax in the Transit Lounges: Changi Airport offers numerous lounges where you can relax, take a shower, enjoy complimentary food and drinks, and even catch some sleep in comfortable recliners or private sleeping areas. Many lounges offer amenities like massage chairs, entertainment facilities, and workstations.
5. Experience the Entertainment Zones: Discover the various entertainment options available at Changi Airport. Enjoy free movies at the Movie Theatres, challenge yourself with gaming consoles at the Xbox Kinect or PlayStation areas, or immerse yourself in virtual reality experiences at the Virtual Reality Zone.
6. Indulge in Dining: Changi Airport boasts a wide array of dining options, ranging from local Singaporean cuisine to international favorites. Sample local dishes like laksa, chicken rice, or chili crab, or explore the international cuisines on offer. There are also plenty of cafes, bars, and lounges to relax and enjoy a drink.
7. Shop Duty-Free: If you’re interested in shopping, Changi Airport offers an extensive range of duty-free shops, luxury boutiques, and specialty stores. Whether you’re looking for electronics, fashion, cosmetics, or souvenirs, you’ll find a vast selection to browse and shop.
8. Catch up on Rest: If you prefer a more relaxed layover, you can find quiet corners or designated rest areas where you can catch up on sleep or enjoy a peaceful moment.

Remember to consider the current COVID-19 restrictions and guidelines in place at the airport and in Singapore. Check the airport’s website or contact the airport authorities for the most up-to-date information regarding facilities, attractions, and safety measures during your layover.