THE JUNGLE INSIDE A CAVE: A roof collapse ages ago in Hang Son Doong (Phong Nha-Ke Bang National Park, Bo Trach District, Quang Binh Province, Vietnam) let in the light; plants thickly followed. Here, “Sweeny” Sewell climbs to the surface as hikers struggle through the wryly named Garden of Edam. Photo by Carsten Peter.