The travel hub in Singapore has had a 135,700 square-metre space installed to link its four terminals together and it includes the world's highest waterfall.
The HSBC Rain Vortex - which stands at 40 metres or so - can be heard before it is seen from the nearby retail and dining outlets within the building.
Jayson Goh, managing director for airport operations management of Changi Airport Group, told CNN Travel: "Rainwater is collected and it becomes a part of the Vortex as well. We can actually control the volume of flow. Below the Vortex we have tanks to collect the rainwater so that we can recycle it. When there's an excess of rainwater, it can be used for irrigation of the plants in the Forest Valley."
The Jewel complex also features a Skytrain, which connects Changi terminals 1, 2 and 3, as well as Canopy Mazes, Sky Nets and a Canopy Bridge.
Explaining the idea behind it, architect Moshe Safdie, said previously: "I wanted to explore a new kind of urban space, a space you go to as a matter of course, because you need to shop, because you're flying out somewhere, and yet it's a garden - somewhere that says 'let's rethink what the public realm is, let's rethink what it is to shop.' I think one of the reasons [we won] the bid was that the other submissions looked like malls and felt like malls, while this one, you don't think of it as a mall, because it's a new kind of experience. It makes us rethink what urban centres could be like if we stretch our thinking."