Leopard sleeping in a tree in savanna, Masai Mara National Reserve, Kenya (© Klein & Hubert/Nature Picture Library)

Small lake and marsh in Jasper National Park in Alberta, Canada (© Don White/Getty Images)

Koi fish, Lan Su Chinese Garden, Portland, Oregon (© Greg Vaughn/Getty Images)

Grape hyacinths and tulips, Keukenhof Gardens, Lisse, Netherlands (© Martin Ruegner/Getty Images)

Belém Tower on the bank of the Tagus River, Lisbon, Portugal (© f9photos/Getty Images)

Spectacled bear resting in tree, Ecuador (© Andy Rouse/Nature Picture Library)

The glass dome of Galleria Vittorio Emanuele II, Milan, Italy (© PhillipMinnis/Getty Images)

Pink apple blossoms, Avila Beach, California (© Mimi Ditchie Photography/Getty Images)

Galápagos penguins swimming, Galápagos Islands, Ecuador (© Henley Spiers/Nature Picture Library)

Forest hammock of slash pine and saw palmetto, Everglades National Park, Florida (© Mary Liz Austin/Alamy)