>> reporter: visitors come from all over japan to experience the ride up for a start, everyone hasasas pt on a helmet. we going there? no way! >> reporter: at its steepest point, the incline reaches 35 degrees. >> translator: you've got to be kidding! >> reporter: the monorororororo forest. if you're lucky, the driver may stop to let you take some snaps and to give a little lecture on the scenery. >> translator: okay. here's the best photo spot. those moss covered shapes are limestone. they turn like that due to erosion from the rain. >> reporter: they carry on, up to the cave. the magical formations are created by nature. when it's time to head home, another surprise awaits. >> translator: we're traveling backwards? >> translator: we go back down facing the same way we came up. it's not good for people to do everything facing forward. sometimes you just have to go backwar backwards. >> translator: it was so scary. you can't see where you're going. >> translator: it was exciting, and the cave is a mysterious, wonderful place. very energizing and filled with power. it's a great deal. >> re