Honoring Jimmy Carter
The US Capitol dome with flags flying at half-staff in honor of former President Jimmy Carter, Washington, DC (© J. David Ake/Getty Images)

Bubbles, bubbles everywhere
Abraham Lake, Alberta, Canada (© Basic Elements Photography/Getty Images)

Bubbles, bubbles everywhere
Abraham Lake, Alberta, Canada (© Basic Elements Photography/Getty Images)

Arches of a bygone era
Heri es-Swani in Meknes, Morocco (© Calin Stan/Shutterstock)

Arches of a bygone era
Heri es-Swani in Meknes, Morocco (© Calin Stan/Shutterstock)

Sharp vision in the depths
Crescent-tail bigeye fish in the Great Barrier Reef, Australia (© Fred Bavendam/Minden Pictures)

Sharp vision in the depths
Crescent-tail bigeye fish in the Great Barrier Reef, Australia (© Fred Bavendam/Minden Pictures)

'Welsh' you a Happy Hen Galan!
Cottage with Tŵr Mawr Lighthouse in the background, Ynys Llanddwyn, Wales (© Westend61 on Offset/Shutterstock)

'Welsh' you a Happy Hen Galan!
Cottage with Tŵr Mawr Lighthouse in the background, Ynys Llanddwyn, Wales (© Westend61 on Offset/Shutterstock)

Calmness overload
Village of Zahara de la Sierra overlooking Zahara-El Gastor Reservoir, Cádiz province, Spain (© SEN LI/Getty Images)

Calmness overload
Village of Zahara de la Sierra overlooking Zahara-El Gastor Reservoir, Cádiz province, Spain (© SEN LI/Getty Images)

Where the past is always present
The Great Court of the British Museum, London, England (© Cavan Images/Offset/Shutterstock)

Where the past is always present
The Great Court of the British Museum, London, England (© Cavan Images/Offset/Shutterstock)

A monumental milestone
High Peaks Trail in Pinnacles National Park, San Benito County, California (© yhelfman/Getty Images)

A monumental milestone
High Peaks Trail in Pinnacles National Park, San Benito County, California (© yhelfman/Getty Images)

Pouch perfect
Brown pelican, San Diego, California (© Arthur Morris/BIRDS AS ART/Getty Images)

Pouch perfect
Brown pelican, San Diego, California (© Arthur Morris/BIRDS AS ART/Getty Images)

1,001 New Mexican dunes
Sunset at White Sands National Park, New Mexico (© Image Professionals GmbH/Alamy)

1,001 New Mexican dunes
Sunset at White Sands National Park, New Mexico (© Image Professionals GmbH/Alamy)

A grotto fit for a god
Neptune's Grotto, Sardinia, Italy (© Carlo Murenu/Getty Images)

A grotto fit for a god
Neptune's Grotto, Sardinia, Italy (© Carlo Murenu/Getty Images)