Cascades of mammoth ferns flourish in the humid air trapped between the narrow walls of Claustral Canyon. First explored in 1963, the formation was named for its claustrophobia-inducing passages and ranks among the regions most visited canyons. (Photograph by Carsten Peter)
HypnoBirthing Portland, OR: Classes - Blossom Clinic birth classes with Lori Reising, LMT. 5 week course.
These are the impressive Škocjan Caves in Slovenia , where the Reka River disappears deep underground. People have lived in the caves since prehistoric times, and the internal atmosphere even has its own eco-system.
stakkholtsgja Gorge in Thorsmork, Iceland.
In pictures: Inside Hang Son Doong, the world's largest caves in Vietnam
DA NANG World’s Biggest Cave, Found in #Vietnam >>> Start Planing your #Trip to #Vietnam 2014
Hike the most dangerous hike in the world, Huashan Mountain.