Florida red-bellied turtle in Rainbow Springs, Rainbow Springs State Park, Florida

A Burchell's zebra and a cattle egret at the Rietvlei Nature Reserve in South Africa

Albion Falls, Hamilton, Ontario, Canada

Honey bee flying over crocuses in the Tatra Mountains, Poland

Glass bridge of Zhangjiajie, Hunan, China

Museum at Prairiefire, Overland Park, Kansas

Salt ponds of Maras in Peru's Sacred Valley of the Incas

Burrowing owl chicks gaze out from among flowers near the Pawnee National Grassland in Colorado

Panoramic view of the Bernina Range with blood moon, Eastern Alps, Engadin, Switzerland

Windmills, Kinderdijk, Netherlands

Masai giraffe in Maasai Mara, Kenya

Nurses serving with the American Red Cross in Paris, France, in May 1919

The village of Oia on the island of Santorini, Greece

Panther Creek Falls in spring, Gifford Pinchot National Forest, Washington

View of Göreme from an observation deck, Göreme National Park, Cappadocia, Turkey

Koala mother and 8-month-old joey, Queensland, Australia

Swedish telescope at La Silla ESO Observatory, Chile

A path winding through a forest carpeted with bluebells in Hertfordshire, England

Tree in blue agave field in the tequila-producing region near Atotonilco el Alto, Jalisco, Mexico

Wadi Rum, Jordan