NEC ENIM ULLUM HOC FRIGIDIUS FLUMEN ATTIGI“I have never touched a colder river than this.” Atticus, dipping his foot in the Fibreno. Cicero, On the Laws II, 6
Lake Posta Fibreno
A spring-fed lake with clear, always cold water, an island that moves by itself and a fish that lives nowhere else. You can walk there from our house.
A lake born from the rock
The lake has no real inflowing river: it is fed by karst springs that collect water from a vast underground basin which, according to the reserve's studies, is linked to the upper Sangro Valley in Abruzzo. It is about 1.9 kilometres long, at most about 320 metres wide and on average less than three metres deep. The Fibreno river rises here and joins the Liri a few kilometres downstream.
Because the water flows constantly from the springs, the temperature stays almost the same all year round and the water is exceptionally clear. Divers, canoeists and the people who come to watch birds among the reeds know this well.
To protect this balance, in January 1983 the Lazio Region established the Lake Posta Fibreno Regional Nature Reserve.
La Rota
The island that walks
In a circular patch of water among the reeds floats La Rota: an island of peat, rhizomes and roots about thirty metres across, with trees that have stayed dwarf. It is not anchored to the bottom. The wind and the currents from the springs slowly push it from one edge to the other.
The dialect name comes from its shape, round like a wheel (ruota). The Italian National Trust (FAI) has listed it among its Places of the Heart.
Pliny the Elder, in the second book of his Natural History (1st century AD), collects the cases of islands floating on Italian lakes. Local tradition, also taken up by the FAI and VisitLazio, sees La Rota as one of the wonders described two thousand years ago.
Cicero and the Fibreno
The river where Cicero sat and wrote
Marcus Tullius Cicero was born in 106 BC in the family villa near Arpino, on the banks of the Fibreno. In his dialogue On the Laws, written at the end of the 50s BC, he sets the conversation with his brother Quintus and his friend Atticus right here: they walk along the river and sit on a small island where the Fibreno splits into two branches and then rejoins.
It is on this page that Cicero calls these places his “real homeland”, the place of his family's roots and the traces of his ancestors. Atticus, touching the water with his foot, is amazed that it is so cold. Visitors to the lake today have the same experience.
Where the Fibreno flows into the Liri, the Abbey of San Domenico was founded in 1011, on the site said to be Cicero's family villa. Discover the abbey · The whole history, in order.
Haec est mea et huius fratris mei germana patria. Hinc enim orti stirpe antiquissima sumus.
“This is the real homeland of my brother and me. From here we spring, from a most ancient stock.”
Cicero, On the Laws II, 3Curiosities
Nine things to know before you go
A fish found only here
The Fibreno trout, or carpione (Salmo fibreni), is an endemic salmonid: in the wild it exists only in this lake. It spawns in winter and hides among rocks and deep vegetation.
The nàue
The lake's fishermen still use a traditional flat-bottomed boat, the nàue. You can see it from the reserve's boardwalks.
The 1810 mill
The little red house at the entrance to the lake is a water mill working since 1810, restored by the town with its original machinery. You can visit it through the Visitor Centre.
Lago Chiaro
From the mill a short path leads to Lago Chiaro, the spot where the water is clearest. Suitable for children too.
The name
According to one tradition, “Fibreno” comes from the Latin fiber, the beaver, an animal that once lived on its banks. “Posta” would mean a well-placed spot.
The lake museum
In the village, in the old school, the Natural History and Ethnographic Museum tells the story of the lake's nature and of the fishermen's life in the past.
Seen from afar
In 2025 CNN listed the lake's springs among eight Italian destinations far from mass tourism.
By bike from the waterfalls
In the first half of October the Ciclostorica “from the waterfalls to the lake” takes place on vintage bikes, from Isola del Liri to the Fibreno and back.
Rare birds
More than a hundred species nest and winter in the reed beds, including the ferruginous duck, a species of European concern.
The lake is one kilometre from the house
Early in the morning, before the visitors arrive, a walk by the lake is the best way to start the day.