The Ring of Brodgar, Orkney, Scotland (© Paul Williams - FunkyStock/Getty Images)

Medieval city walls, Ávila, Spain (© Alberto Loyo/Getty Images)

American black bear cub in spring, Shenandoah National Park, Virginia (© Scott Suriano/Getty Images)

Union Square in lower Manhattan at twilight, New York (© Sean Pavone/Getty Images)

The RedBall Project art installation, Centraal Station, Antwerp, Belgium (© Brit Worgan/Getty Images)

Sunset on Bowling Ball Beach, Mendocino County, California (© Melo Qiao/Getty Images)

Apple trees in spring, Germany (© Smileus/Getty Images)