Explore nine vibrant displays of plant life from five different continents at the Flower Dome in Singapore, which unsurprisingly is the largest glass greenhouse in the world. Or visit the equally impressive Cloud Forest instead, which boasts a 115-foot (35-meter) waterfall, spectacular views, and mysterious plants. End with a stop at Marina Bay Sands Skypark and observe the city from 650 feet (200 meters) in the air.