Over the last 20 years, readers have submitted more than 470,000 images to Smithsonian’s annual photo contest. These photos have transported us to the far corners of Earth, captured spectacular, split-second moments and introduced us to fascinating people and unique landscapes.

The Grand Prize, Readers’ Choice prize, Natural World, Travel, People, The American Experience, Artistic Images and Drone/Aerial category prizes are open to photographers who are 18 years old or older.