George Peabody Library, Baltimore, Maryland (© Wim Wiskerke/Alamy)

Gaztelugatxe at sunset, Basque Country, Spain (© Eloi_Omella/Getty Images)

The National Cherry Blossom Festival in Washington, DC (© f11photo/Getty Images)

Rainbow over Wasson Peak, Saguaro National Park, Arizona (© Frank Staub/Getty Images)

Sandstone formations in the badlands near Caineville, Utah (© Chris Moore/TANDEM Stills + Motion)

Tree frog, Costa Rica (© Ondrej Prosicky/Shutterstock)

Ostuni at dusk, Apulia, Italy (© Feng Wei Photography/Getty Images)

Aerial view of Sydney Harbour, New South Wales, Australia (© jamenpercy/Getty Images)

Superbloom in Carrizo Plain National Monument, California (© Robb Hirsch/TANDEM Stills + Motion)

Female black-naped monarch nesting (© komkrit tonusin/Alamy)