This 1.6km/1mi lava cave is open to visitors, with torches for hire at the entrance - the temperature in the cave is a constant 5.5°C/42°F throughout the year. Next to the cave, a circular path (1.6km/1mi) crosses a surrealist landscape formed by a pine forest which was petrified 6 000 years ago when molten lava covered the trees, burning them and leaving hollow lava moulds in their place.