Natural arch in Vratna River Gorge in eastern Serbia.

Natural arch in Vratna River Gorge in eastern Serbia.

Vikos Gorge in Pindus Mountains, Epirus, Greece

Vikos Gorge in Pindus Mountains, Epirus, Greece

Fall at the lake, Hinterer Langbathsee / Austria

Fall at the lake, Hinterer Langbathsee / Austria

Peyto Lake fog lifting early in the morning, Alberta, Canada

Peyto Lake fog lifting early in the morning, Alberta, Canada

Cave called ‘The Cathedral’ in Tsingy de Bemaraha National Park, Madagascar

Cave called ‘The Cathedral’ in Tsingy de Bemaraha National Park, Madagascar