Jeju-do Island

情况：

Jeju-do (also spelled Chejudo) is Korea's largest Island, located well south of the western side of the peninsula.  Above is a panorama of Jeju's natural beauty: under a typically cloudy sky, the 1950 meters high peak of Halla-san dominates its alpine slopes, above jungle-thick coastal forests
transversed by high gushing waterfalls.

The Sanbang-gul (Mountain-Room Cave), high up on the slope (requiring a steep 15-minute climb on stairs) is the only cave-shrine on Jeju, and has long been famous for Buddhist worship. To protect the visitors against rockfalls, a specific solution had to be found.