Ms. Yumoto taught me the basic knowl-edge needed to understand Shiga Highland UNESCO Eco Park. First of all, my guide told me, the soil in this area, produced from volcanic eruptions, comprises a basic layer of red soil consisting mainly of lava, a layer of black soil consisting of humus (decomposed organic matter) mixed with weathered stone, and an upper layer of leaf litter and humus. She also explained that the virgin forest in this area was formed mainly by five trees: the Japanese thuja (kurobe), Veitch’s silver fir (shirabiso), Maries’ fir (ohshirabiso), spruce (tohi), and Northern Japanese hemlock (kometsuga). Smelling the leaf of a Northern Japanese hemlock, Ms. Yumoto added that the best time to go walking in the forest is morning, which is when we started out, because that is the time of day when trees emit the most phytoncide, an antimicrobial volatile compound.