The karstic complex of Onferno is considered to be among the most important in Italy both because of the caves and the chalk. It unwinds beneath the castle and parish, and originates from the erosive action of a little underground torrent, which about fifty to one hundred thousand years ago excavated its course in the dephts of the great mass on which the "Castrum Inferni" rose.
In Riyadh, Saudi Arabia, the Onferno site has been recognised as a UNESCO UNIVERSAL HERITAGE.
It is made of grey selenite chalk from the Inferior Messianic period (5-6 million years ago), transported to Onferno a long long time ago, during some movements of the Earth's crust. In this mass the ever active river has created deeply grooved meanders, great underground rooms and long pieces of hanging chalk, which stick out, in the vaults, in various shapes. Today only a small stream of the old river remains, which runs to the right and the left of the course, fed by two courses, which start in the sala of Mammelloni (the Knoll Room). The first naturalist who attempted scientific exploration of the caves was Ludovic Quarina in 1916.
A warning regards clothing: the cave has an average temperature of 12-14 degrees therefore we advise you to avoid too summery clothes and to take a light jacket with you, comfortable shoes too and rubber soles, considering that the course has been maintained as "natural" as possible and humidity often makes the route slippery.
Reservation recommended. Access to the caves could be temporarily suspended during the year related to the protection of wildlife, maintenance or temporary unavailability of routes.
- Educational centre
- Meeting room with facilities
- Guide services
- Not accessible to disabled guests
Rates of entry include entrance to the Oriented Nature Reserve, Visitors’ Centre and Museum
How to get there:
By car: from Rimini take provincial road: SP 31 to Coriano and then provincial road SP 18 to Gemmano
For a limited number of visits, telephone booking is recommended. The visit is always accompanied by a
Duration: about 90 minutes in summer, 60 minutes in winter
Comfortable clothing is recommended, trekking shoes or boots with studded soles, and a light waterproof jacket (inside the cave the temperature is around 12°C all year round).
Helmets with lighting are provided for the visit.
Before or after the visit, it is possible to visit the Nature Museum and the Botanical Garden for free.
For GROUPS and SCHOOLS, it is possible to organize personalized visits on the days and times of
preference, even on days and at times that do not fall withing the scheduled opening hours.
All year long visits by reservation can be made for groups (minimum 15 people) even on days and at times
that do not fall within the ordinary opening hours.
Access to the caves could be temporarily suspended throughout the year for reasons of protection of the
fauna, maintenance, or temporary unavailability of the pathways.
visitor center educational workshops for a fee
equipped multipurpose room
The site is not accessible to people with disabilities
How to get there:
by car: from Rimini, take provincial road SP 31 to Coriano. After leaving the town, at the roundabout
continue on along the provincial road SP 18 in the direction of Gemmano. Then follow the road signs for ''Grotte di Onferno''
Open all year round
Admission: for a fee
Full rate: 10.00 euros; Reduced rate: 8.00 euros
For visits and information:
Via Provinciale Onferno, 50 - Onferno Castle, Gemmano (RN)