Ghosts of the gold rush
Bodie State Historic Park, Mono County, California (© Julien McRoberts/Tetra Images, LLC/Alamy)

The heights of horror
The Mont Blanc massif, near Chamonix, France (© Simon Schöpf/Getty Images)

The heights of horror
The Mont Blanc massif, near Chamonix, France (© Simon Schöpf/Getty Images)

Into the woods
Gespensterwald, Nienhagen, Mecklenburg-West Pomerania, Germany (© mauritius images GmbH/Alamy)

Into the woods
Gespensterwald, Nienhagen, Mecklenburg-West Pomerania, Germany (© mauritius images GmbH/Alamy)

A mother's warmth in the cold
Polar bear mom and cub, Churchill, Manitoba, Canada (© Design Pics/plainpicture)

A mother's warmth in the cold
Polar bear mom and cub, Churchill, Manitoba, Canada (© Design Pics/plainpicture)

It's carving time
Pumpkin field, Victoria, British Columbia, Canada (© Shaun Cunningham/Alamy)

It's carving time
Pumpkin field, Victoria, British Columbia, Canada (© Shaun Cunningham/Alamy)

Hoots and haunts
Great horned owl (© Mark Newman/Getty Images)

Hoots and haunts
Great horned owl (© Mark Newman/Getty Images)

A haunting history
View of Edinburgh Castle from a churchyard in Scotland (© Chris Dorney/Alamy)

A haunting history
View of Edinburgh Castle from a churchyard in Scotland (© Chris Dorney/Alamy)

Stone-cold stares on Halloween
Chimera of Notre-Dame de Paris, France (© scaliger/Getty Images)

Stone-cold stares on Halloween
Chimera of Notre-Dame de Paris, France (© scaliger/Getty Images)

Celebrating America's Native heritage
Pueblo ruins, Hovenweep National Monument, Utah (© Alan Majchrowicz/Getty Images)

Celebrating America's Native heritage
Pueblo ruins, Hovenweep National Monument, Utah (© Alan Majchrowicz/Getty Images)

From near extinction to national icon
American bison in Yellowstone National Park, Wyoming (© Ian Shive/TANDEM Stills + Motion)

From near extinction to national icon
American bison in Yellowstone National Park, Wyoming (© Ian Shive/TANDEM Stills + Motion)

Nurturing nature
Caribbean flamingo nests, Ría Lagartos Biosphere Reserve, Yucatán, Mexico (© Claudio Contreras/Minden Pictures)

Nurturing nature
Caribbean flamingo nests, Ría Lagartos Biosphere Reserve, Yucatán, Mexico (© Claudio Contreras/Minden Pictures)