This is the trip's final destination - and one of the most unusual places in Japan. Osorezan, or Mt. Dread, is the interior of an extinct volcanic crater (and a rough climb on a bike!) that is revered as the home of the spirits by the Ainu, Japan's original inhabitants. The place is full of sulfur fumes and bubbling pools, and while it's not all THAT eerie, it has a mood that soon grows on you.
Everywhere around the still waters of the crater lake are piles of stones supposedly put up by the dead as makeshift Buddhist stupas, in order to give them more merit-badges for entrance to paradise (even heaven apparently works on the points system). Some people leave straw sandals here as offerings for the guardians who patrol the area to make sure nobody knocks over the piles. Presumably they don't get any school group tours, or the guardians would have their hands full...