Poster for Teacher Appreciation Week by 12-year-old Caroline Holt, 7th-grade student at the Bush School, Seattle, Washington

Burchell's zebra stallions, Rietvlei Nature Reserve, South Africa

Cherry blossoms at the Japanese Tea Garden in Golden Gate Park, San Francisco, California

'The Spirit of Harlem' mural by Louis Delsarte in Harlem, New York City

Aerial view of tidal channels in marshland of the Mockhorn Island State Wildlife Management Area, Virginia

Northern gannets on Great Saltee Island, Ireland

Yayoi Kusama's 'Pumpkin' artwork on Naoshima Island, Japan, in August 2018

Wensleydale, Yorkshire Dales National Park, North Yorkshire, England

Adélie penguins diving off an iceberg in Antarctica

The Cholla Cactus Garden in Joshua Tree National Park, California

Casa Batlló in Barcelona, Catalonia, Spain

Mississippi River on the border between Arkansas and Mississippi

The north coast of Madeira, Portugal

Tegallalang Rice Terraces, Ubud, Bali, Indonesia

Large school of Munk's devil rays seen from the air, Gulf of California, Mexico

Montalbano Elicona, Messina, Sicily, Italy

New River Gorge Bridge in the New River Gorge National Park and Preserve, West Virginia

Dalí Theatre-Museum in Figueres, Spain

Jackie Robinson signs autographs at spring training in Ciudad Trujillo, now Santo Domingo, Dominican Republic, on March 6, 1948

Wildflowers in the Carrizo Plain National Monument, California