Earth Hour was this weekend, so people worldwide turned off their lights for an hour as a symbolic environmental gesture. Head here for more.

New York:

New York’s Times Square before, top, and during Earth Hour on Saturday. (Eduardo Munoz/Reuters)

The Empire State Building moments before and after going dark for Earth Hour. (Timothy A. Clary/Agence France-Presse via Getty Images)

Washington, D.C.:

The National Cathedral dimmed its lights on Saturday. (Mandel Ngan/Agence France-Presse via Getty Images)