The official campground is on the edge of the Solfatara Crater. The entrance is a bit small but…
The vulcano Solfatara is situated 10km west of Napoli. It is a “sleeping” vulcano which belongs to the Phlegräic Fields. The crater is walkable, the steps sound hollow on the hot ground.
There are hot sulfur springs (fumaroles) and bubbling mud.
In earlier times the crater was used as a natural sauna. The brick-built chambers are still there.