The finalists in the 11th annual Smithsonian Photo Contest have been announced, and you can help choose the winner.

After looking through more than 50,000 photographs submitted by photographers from 132 different countries, the judges selected ten from each of six categories: The Natural World, Travel, People, Americana, Altered Images and Mobile.

In this gallery, we feature a selection from three of the categories. Head over to smithsonian.com before 6 May to cast your vote for the Readers' Choice award.