Walking around downtown Phoenix at night, you can find plenty of art to take in, from murals to sculptures. But there's only one gigantic cloud-shaped structure suspended over the city. Since 2009, "Her Secret Is Patience" by Janet Echelman has loomed benevolently over the area now called Civic Space Park. It's constructed from steel, polyester twine netting and colored lights, giving the impression of a glowing cloud formation or perhaps a stationary tornado. It's an impressive enough piece during the day, when the bones of the project are visible, but it's best seen at night, when it lights up the city.