An impressive field of fumaroles was developed on the Komatsu Jigoku site in the stunningly beautiful Aso-Kuju Nature Park. A wooden path on stilts with handrails allows visitors to safely observe these mini-craters and bubbling ponds. The sulphur permeating the air has coloured the surrounding rock a distinctive yellow and the hydrogen sulphur from the melting magma gives off an equally distinctive and pungent scent.