The Gordale beck flowing through the narrow limestone gorge of Gordale Scar, North Yorkshire, England, United Kingdom, Europe

Hikers on walkways admire the creek through the limestone gorge, Aare Gorge, Bernese Oberland, Canton of Berne, Switzerland, Europe

Water of creek flows in the narrow limestone gorge carved by river, Aare Gorge, Bernese Oberland, Canton of Berne, Switzerland, Europe

Water of creek flows in the narrow limestone gorge carved by river, Aare Gorge, Bernese Oberland, Canton of Berne, Switzerland, Europe

Hiker on walkway admires the creek in the narrow limestone gorge, Aare Gorge, Bernese Oberland, Canton of Berne, Switzerland, Europe

Walkers on a narrow mountain road above the Cares Gorge, 1000m deep, 12km limestone gorge, in the Picos de Europa mountains in Cantabria, Spain, Europe

Hiker on walkways admires the creek in the narrow limestone gorge, Aare Gorge, Bernese Oberland, Canton of Uri, Switzerland, Europe

Aghazadeh Mansion and its windcatcher, Abarkuh, Yazd Province, Iran, Asia

Inside Daugbjerg limestone mines near Viborg, Jutland, Denmark, Europe

Cheese transporter passing narrow tunnel to the Monsted, Monsted limestone caves near Viborg, Jutland, Denmark, Europe

A travertine tower in Ascoli Piceno, Marches, Italy, Europe

SLOVENIA Trenta Valley Soca River Viewed from Felika Korita Soce a narrow wooden suspension bridge flowing through rocks shaped by the power of the water Clear blue water narrow gorge limestone rocks clean water important river