The crater was formed approximately 3,700 years ago during the terminal phase of the Phlegraean Fields volcanic activity.
The interior of the crater functions as a natural thermal inversion zone, creating a microclimate that allows Mediterranean vegetation to flourish alongside species more typical of northern forests.
Historically, the site was used as a royal hunting reserve by the Bourbon kings, who enclosed the perimeter with stone walls that remain partially visible today.
The reserve contains a rare 'fumarole' soil condition that supports specific calcicolous plants.
The lake system within the crater is fed by groundwater seepage, providing a stable habitat for migratory waterfowl.
The dinosaur statues are part of a didactic project intended to illustrate the evolution of life within a geological setting.
The Riserva Naturale Oasi WWF Cratere degli Astroni is a unique nature reserve situated within a dormant volcanic crater of the Phlegraean Fields. It is the only WWF oasis located in an ancient volcanic basin, characterized by a microclimate that supports diverse flora and fauna distinct from the surrounding urban area of Naples. The reserve features a circular caldera approximately 6 kilometers in circumference. Visitors can traverse internal paths that showcase a landscape shaped by geothermal activity. The site is currently recognized for its educational programs, including a permanent exhibition of large dinosaur replicas placed within the woodland. The crater floor houses two lakes, Lago Grande and Lago Cofani. The reserve serves as a sanctuary for numerous bird species, including waterbirds, and serves as a site for biodiversity research.
The elevated overlook paths providing a panoramic view across the caldera towards the central lakes.
Wear sturdy, closed-toe hiking boots as the terrain is uneven, volcanic, and can be muddy.
Bring binoculars for birdwatching near the lake perimeters.
Apply insect repellent before entering, as the dense vegetation and water bodies attract mosquitoes.
Do not attempt to hike the entire crater perimeter in a single trip without adequate water and physical preparation.
Generally closed on Mondays and Tuesdays; always check for seasonal closures during the winter months.
Stay strictly on marked paths to protect the delicate volcanic ecosystem and avoid disturbing wildlife.
