Drones can be controversial. As unmanned flying vehicles that can stealthily spy or drop weapons on people, they’ve been the subject of intense ethical and national security debates. But drones don’t have to be military machines. In the hands of photographers, smaller unmanned vehicles can capture beautiful, unique images that would otherwise go unseen.

For the third year in a row, the international Dronestagram contest has recognized outstanding drone photos in this emerging field.

“A great drone picture is a picture that you immediately identify as a drone photo,” says Guillaume Jarret, Dronestagram’s head of marketing and development. “It is taken at a low altitude, near the target of the picture.” If you know what to look for, you can figure out that these pictures couldn’t have “been taken with a device other than a drone.”

Patrick Witty, one of the contest judges (and also National Geographic’s deputy director of photography for digital), says that capturing these types of photos is “incredibly difficult.”

“Until you are floating above a scene, it’s impossible to know exactly what you’ll see below,” he says. “Photographers not only have to pilot the drone but, more importantly, compose a photo that transports you to a place you've never been before.”

The nine photos in this gallery showcase the top three winners in each category: Nature-Wildlife, Sports Adventure, and Travel. They were selected from 5,900 entries spanning 28 countries. Together, they speak to what Jarret says is the purpose of this contest: “to celebrate the beauty of drone photography, a new photographic language.”