Cunicoli di Claudio

Tunnels of Claudius


Useful Information

Location: Via Alfredo Nobel, 67051 Avezzano AQ.
From the roundabout take Via Alfredo Nobel for 350 m, parking lot on the left side of the road. Follow unsigned road uphill.
(41.988810, 13.434190)
Open: currently closed due to Corona.
[2021]
Fee: currently closed due to Corona.
[2021]
Classification: SubterraneaSubterranea Museum SubterraneaSewage System KarstPolje KarstPonor
Light: LightIncandescent Electric Light System
Dimension: L=5,653 m, VR=8.44 m.
Guided tours: self guided
Photography: allowed
Accessibility: no
Bibliography: Ezio Burri (2002): Il parco naturalistico archeologico dei cunicoli di Claudio (Avezzano, Italia centrale) Firenze - Associaz. Naz. dei Musei Scientifici (estratto da Museologia scientifica).
Address: Cunicoli di Claudio, 1 Via E. Forlanini, Avezzano, 67051, Tel: +39-0, Fax: +39-0,
Borgo Incile, Via Cavour, 67051 Avezzano AQ, Tel: +39-339-743-1107.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.

History

42-51 constructed during the reign of Claudius.
98-117 according to Tacitus and Pliny, Trajan had the tunnel cleaned.
117-138 improvement works carried out under Hadrian.
13th cty failed restauration attempt by Frederick II of Hohenstaufen.
1790 failed restauration attempt by Ferdinand I of the Two Sicilies.
10-JUL-1854 reconstruction started, financed by the Roman banker Alessandro Torlonia.
1870 reconstruction completed.
01-OCT-1878 lake officially completely drained.
1902 declared an Italian national monument.
JUN-1977 Archaeological Park of Claudius established.
2017 funds allocated for the development of the park.

Description

Cunicoli di Claudio (Tunnels of Claudius) are located at the foot of Monte Salviano, south of the city of Avezzano. By the locals they are often called Cunicoli di Nerone (Tunnels of Nero), but that's a misnomer. It's only a single tunnel, and it was constructed between 42 and 51 AD during the reign of Roman Emperor Claudius. He commissioned the construction of the system of canals, tunnels, and wells.

The tunnel was the first attempt to drain Lake Fucino. The huge lake covered a big area in the middle of the Apennin mountain ridge. Surrounded by mountains on all sides the melting water of the last ice age filled the large tectonic depression with a huge lake, sediments from the glaciers were deposited and created a huge plain. Since the Bronze Age this area was important for agriculture, as the plains surrounding the lake were quite fertile. Unfortunately the lake had no outflow on the surface, it was drained underground by karst caves. There was only one natural swallow-hole located at Petogna near Luco dei Marsi, which was often clogged. When the sink clogged, the rising water level flooded the fields destroying the crops and even flooded the surrounding villages. The lowering of the water level in summer was also a problem, as the areas that fell dry were swampy, which led to serious health problems for the population. Also, there was the ambitious aim to build a road connecting the Tiber with the Adriatic Sea through the Apennine Mountains. But in the Piana del Fùcino (Fùcino Plain) it would have been subject to flooding. The local inhabitants were called the Marsi and they pressed Julius Caesar to drain the lake. But he was killed before he was able to provide the necessary funds.

The project to drain the lake was started during the reign of Roman Emperor Claudius. The first idea was to build a canal through the low Cesolino hill, so the lake waters would flow into the Salto River. This idea was abandoned because the water would have finally flown into the Tiber, and thus could represent a flood threat for Rome. The plan to dig a tunnel through Mount Salviano into the Liri River was the second possibility, and was executed by Emperor Claudius in year 41 with a substantial public financing. 30,000 men, slaves and workmen, dug the tunnel, a dam, and a drainage channel which still exists. The lock in the dam allowed to control the outflow. When the works were concluded in 51 there was a great opening celebrating Emperor Claudius in the presence of his wife Agrippina and the young Nero. The celebrations included a naumachia, a naval battle on the lake, with over fifty galleys divided into two fleets, which were called the Sicilians and the Rhodites. One fleet was manned by slaves and the other by convicts.

There was always the threat of landslides, as several parts of the rock are not very stable, and despite the walls which were erected, there is always the danger that the tunnel is blocked by sand. Also the whole area is volcanic and subject to earthquakes, which ae also a thread for obvious reasons. Even the naval battle at the inauguration was threatened by landslides, and not working sluices.

The tunnel was dug by hand, and with a section between 5 m² and 10 m² it was a lot of work. To speed up the construction and make sure the tunnel goes into the right direction a series of 20 wells was constructed which where then connected at the bottom. So with the entrances the tunnel was built at 22 places at the same time. The workers entered through the wells and the removed rock was pulled out at the wells. Depending on the terrain the wells were between 18 m and 122 m deep. As the tunnels did not always meet exactly, small exploratory tunnels which were 80 cm wide, were built. When two sections met, they were widened, probably asymmetrical if necessary. The wells were divided into four sections, two for each team, one each for pulling buckets up and one for lowering the empty buckets again. In addition, numerous inclined tunnels were dug on the slopes, where the overburden was too thick, for the same reason.

When the tunnel was first opened, the waters of the lake dropped only 4.50 m and the emperor ordered a further deepening of the outflow. Finally, the lake area shrank by about 6000 ha and the danger of flood was banned. Afterwards the tunnel worked very well for decades. It was renovated by Trajan and later improved by Hadrian. In this time Marsica became very prosperous and the hills around the lake were transformed into holiday resorts. Around the 6th century Italy was invaded by various "barbarians" and the Roman Empire finally collapsed. The tunnel was not maintained anymore, and due to an earthquake it was blocked. As a result the lake returned to the previous levels. During the Medieval Age all attempts to restore the tunnel failed. Both Frederick II of Hohenstaufen (13th century) and Ferdinand I of the Two Sicilies failed, mostly because of the lack of the necessary funds. Also, the 1826 attempt by Cavaliere Luigi Giura and Commendatore Carlo Afan de Rivera who were commissioned by King Francis I.

The first successful reconstruction was financed by the Roman banker Alessandro Torlonia and executed by Swiss engineer Franz Mayor de Montricher. The work was completed in 1870 by the Swiss site engineer Enrico Samuele Bermont and the French deputy site engineer Alessandro Brisse, assisted by Léon de Rotrou. In 1873 the level of the lake started to sink and in 1876 the reclamation of the lake floor was completed. The lake was completely drained in 01-OCT-1878 and 16,000 ha of fertile farmland created. Subsequently, a second drainage system to the south was created, as a fallback.

In 2017 the Chamber of Commerce of L'Aquila, the municipality of Avezzano and the GAL Terre Aquilane founded the development of the park with 250,000 €. The tunnels have been developed with trails, steps, and electric light. Unfortunately the development was completed in 2020 after the outbreak of Corona and so far the tunnels have not been opened to the public. Nevertheless, it is possible to visit the drainage channel with the Incile del Fucino (Fucine Inlet), the Roman sluice gates which controlled the outflow of water from the lake. The current state though is a result of the 1876 restoration in neoclassical style. It is also possible to see the spectacular entrances to the major tunnel