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Mefite of Valle d'Ansanto

Highlight • Natural Monument

Mefite of Valle d'Ansanto

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The Mefite di Valle d'Ansanto is a truly unique natural monument nestled in the heart of Alta Irpinia, within the province of Avellino, Campania, southern Italy. Situated at an elevation of approximately 674 meters near the town of Rocca San Felice, this site is renowned for its small, bubbling sulfureous lake, often referred to as La Mefite laghetto, and the continuous emission of gases from the subsoil. It stands as a testament to the powerful geological forces at play in…

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    June 15, 2022

    Cycling

    phenomenon of sulphurous origin found in the Ansanto Valley, about 4 km from the town of Rocca San Felice. a place of extraordinary scenic beauty and incredible natural strength due to the continuous bubbling of the waters and the strong gaseous exhalations that come from the cracks in the ground. Recent scientific studies have certified that Mefite represents the non-volcanic phenomenon with the highest concentration of carbon dioxide ever measured in the world.
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    May 27, 2025

    Cycling

    Worth the detour, truly unique and impressive
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    Nearby routes

    Best routes near Mefite of Valle d'Ansanto

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    #1.

    Abbey of Goleto – View of Guardia dei Lombardi loop from Campo di Nusco

    103km

    07:10

    1,830m

    1,830m

    Hard bike ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.

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    Hard

    Hard bike ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.

    Hard

    Hard bike ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.

    Hard

    Details

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    Elevation 670 m

    Weather

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    Tuesday 24 March

    16°C

    2°C

    0 %

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    Max wind speed: 17.0 km/h

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    Location: Rocca San Felice, Avellino, Campania, Italy

    Frequently Asked Questions

    What makes the Mefite di Valle d'Ansanto geologically unique?

    The Mefite is considered one of the largest and oldest cold natural carbon dioxide springs globally. It's an exceptional non-volcanic CO2 degassing site, with continuous emissions of carbon dioxide and hydrogen sulfide from the subsoil. This phenomenon creates a constantly bubbling, muddy lake and a barren, sulfur-stained landscape, making it a significant natural laboratory for scientific study.

    Are there any hiking trails directly around the Mefite di Valle d'Ansanto lake?

    Due to the high concentration of dangerous gases, there are no specific hiking trails directly around the Mefite lake itself. Visitors are advised to maintain a safe distance and observe all marked danger signs. However, the broader Valle d'Ansanto region offers numerous trekking paths for hikers to explore the surrounding natural and cultural landscape.

    What is the historical and mythological significance of the Mefite?

    The Mefite has a rich ancient history, revered by the Osci and Samnites as early as the 7th century BC. It was the site of a sanctuary dedicated to the goddess Mefitis, associated with spring waters, fertility, and the underworld. Ancient authors like Virgil, Cicero, and Seneca described it as an "entrance to the Underworld" or "the breath of Dis" due to its deadly exhalations, highlighting its deep roots in local mythology and belief systems.

    Is Mefite di Valle d'Ansanto suitable for families with children?

    While the Mefite is a fascinating natural wonder, extreme caution is necessary, especially with children. The high concentration of gases near the lake makes the immediate vicinity dangerous. It's crucial to keep children close, ensure they understand the safety warnings, and stay strictly behind marked barriers. The surrounding area offers more suitable, safer paths for family walks.

    Are dogs allowed at Mefite di Valle d'Ansanto?

    Given the lethal nature of the gases, particularly at ground level where animals are more susceptible, it is strongly advised not to bring dogs or other pets close to the Mefite lake. The high concentration of carbon dioxide and hydrogen sulfide poses a significant health risk to animals.

    What kind of unique biodiversity can be found at the Mefite?

    Despite the harsh conditions, the Mefite supports unique extremophile life. Specialized flora, such as a rare variety of broom called Genista anxantica (named after the valley), manages to survive at the crater's edges, adapting to the acidic and inhospitable soil. Some extremophile algae also thrive in the lake's unique environment.

    How long should I plan for a visit to Mefite di Valle d'Ansanto?

    A visit to the Mefite itself, observing the lake from a safe distance, typically takes about 30 minutes to an hour. If you plan to explore the surrounding trails in the Valle d'Ansanto or visit nearby Rocca San Felice, you should allocate more time, perhaps a half-day or full day.

    What are the best ways to get to Mefite di Valle d'Ansanto?

    The Mefite is located about 4 km from the town of Rocca San Felice in the province of Avellino. The most convenient way to reach it is by car, as public transport options are limited in this rural area. Parking is generally available near the site, but it's advisable to arrive earlier in the day, especially during peak season, as spaces can fill up quickly.

    Are there any facilities like restaurants or accommodation near the Mefite?

    While there are no direct facilities at the Mefite site itself, the nearby town of Rocca San Felice offers various options for visitors. You can find local restaurants (ristoranti) serving traditional cuisine, as well as accommodation choices including farm stays (agriturismo) and hotels, providing a base for exploring the region.

    What should I wear when visiting Mefite di Valle d'Ansanto?

    Given the potentially uneven and sulfur-stained terrain, sturdy, closed-toe footwear is highly recommended. Dress in layers, as weather conditions can change, and consider sun protection. While the immediate area is barren, if you plan to hike in the surrounding valley, appropriate hiking attire is advisable.

    Does the Mefite have any connection to seismic activity?

    Yes, the Mefite is sometimes referred to as a "seismic sentinel." Reports suggest that the gas emissions from the Mefite can increase or decrease before seismic events, making it a point of interest for geologists studying earthquake prediction and tectonic processes in the southern Apennines.

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