Nature: Aosta, Aymavilles, Charvensod, Gressan, Jovençan

This particularly interesting area from a geomorphological and archaeological point of view, the hillock with steep slopes and a flat peak is located to the North-East of Aosta and it is also known locally as “Quota B.P.” (from Baden-Powell, scout founder).

A late Neolithic settlement, dating back to 3000 B.C. was situated at the top of the hill.

The nature reserve extends across 14 hectares at an altitude between 720 - 796 meters and offers typical sceneries of low mountain slopes with southern exposure.
The area is an excellent point for birdwatching during the migratory periods, especially for some birds of prey and corvidae. The reserve is also home to some mammals, reptiles and various invertebrate species.

The area’s climate promotes typically xerophile plant species mainly downy oaks and plants of steppe origin.
This conditions make the reserve’s visit possible all year round, with preference for spring and autumn.

How to get there
From the exit Aosta Est of the A5 motorway, take the national road 26 towards the town. At the second roundabout turn right towards Porossan and go on until the Serod hamlet. Continue following the signs to Saint-Christophe until reaching the little parking at the reserve’s entry.

In a very urbanised environment, the traces of a Roman bridge dating back 2000 years are the only precious visible testimony of the ancient bed of the Buthier river. The river, an important tributary of the Dora Baltea, to which it lent its name, now flows near the Arch of Augustus, but up until the 11th century it flowed with a single bed under the Stone Bridge. The city of Aosta develops on the distal section of the large fan of the Buthier river in convergence with the Dora Baltea. From the Roman presence up until the late Middle Ages, the river flowed, with a single bed, under the “Ponte di Pietra”. On an unknown date, which is thought to be prior to the year 1000, following a serious flood, a diversion of the river caused the subdivision of the riverbed into two branches. Documents from the 11th-13th centuries certify the existence of two separate rivers, each of which had a bridge: “lapideus” the Roman one and “ligneus” the more recent one, situated around one hundred metres further west, near the Arch of Augustus.
In a print dated 1682, showing the city of Aosta, we can see that the canal with the largest capacity flowed under the wooden bridge (which has now been replaced by a modern bridge), while under Ponte di Pietra there was only a modest stream. Around 1850, the historian Aubert discovered that the section of riverbed under the Roman bridge was three quarters full of flood debris. Water definitively ceased flowing under the bridge around the first decades of the 20th century. The Roman Bridge, which ceased its function as a link, remains as a testimony of the extraordinary engineering art of the Romans and an evolutionary moment in the route of the Buthier river. The ancient riverbed, near the bridge, was transformed into a green area to be used as a public garden, where there are stones and round and smooth masses, which perhaps once belonged to the old river. The span of the bridge is partially obstructed by a wall that supports a brick terrace. Behind the bridge, the area is completely built-up and there are no recognisable traces of the historical branch of the Buthier river.

How to get there:

You can reach Aosta city either through the S.S. 26 or via the motorway. Arriving from Turin, once you have surpassed the commercial area, follow the signposts for the city centre. Having passed the state road through an underpass, you will reach Corso Ivrea directly. It is possible to park in Via Monte Emilius.

TECHNICAL NOTES
Altitude: 500 m above sea level
Overall duration of the tour: 20 minutes.
Recommended period: All year round

Itinerary:

The geological site is located in Aosta city, coming from the centre of Aosta, go in the direction of the Arch of Augustus and as far as corso Ivrea, the street immediately below the Arch, the bridge and the old riverbed are 100 metres after the first traffic light on the left.

From a naturalistic point of view, the area around Pont d’Ael offers an interesting variety of flora and fauna. It is in fact a special conservation area protected under the European “Natura 2000” network.

Crossing the Roman aqueduct-bridge, there are arid grasslands, abandoned agricultural terraces, alternating with sparse forests of oak and Scots pine, where plant species of steppe and Mediterranean origin grow, such as the_Achillea tomentosa_. There are also some orchids, including the rare Cephalanthera damasonium.

The large quantity of butterflies is also of considerable interest: in addition to the endemic Polyommatus humedasae 96 diurnal species have been counted.

Upstream of the arid prairies rise the rocky walls that form the south-eastern slope of Mount Pognon on which birds of prey such as the golden eagle and the peregrine falcon nest.

Downstream from the village, the Grand’Eyvia torrent creates a shaded gorge with very steep walls, with microclimatic conditions of greater humidity where a forest very rare in the Aosta valley grows with a prevalence of linden, maple and ash trees.

Moulded into a curious shape by the glaciers, a habitat wrapped by sunshine

The elongated spur - the “côte” - originating from deposits of a glacial origin, is one of the most significant elements of this nature reserve, which owes its name to a legend according to which the côte is the little finger of the giant Gargantua, a character invented by Rabelais, buried under a blanket of debris.
An ancient story that accompanies those of the many animal and plant species that live in this typical example of a steppe environment, characterized by grassy-rocky sides and slopes, an arid area with strong sunlight.

Flora
Among the most representative species of the floristic world are the “Artemisia vallesiaca”, a rare aromatic plant and the “Telephium imperati”, of Mediterranean origin.

Fauna
The reserve is an ideal environment for small rodents, birds of prey, passerines, invertebrates and reptiles such as the wall lizard, the green lizard and the rat snake. The entomofauna is particularly rich; in fact, there are numerous species of lepidoptera and beetles typical of arid environments. Thanks to its excellent exposure, the reserve can be visited safely even in the winter months; however, spring and autumn are still the best seasons to enjoy the mild climate and the beautiful colors.

How to Get There
Coming by car from the city center of Aosta, the Côte de Gargantua is clearly visible from the Envers road (road connecting the municipalities of the talweg located on the orographic right side of the Dora Baltea). At the Pont-Suaz roundabout, take the number 20 regional road towards “Gressan - Jovençan - Cogne”. The itineraries that lead to the discovery of the reserve start from different points, but given the limited availability of parking spaces in the small parking lots in the hamlets, it is advisable to leave the car in the areas belonging to the Municipality of Gressan, located on the left side of the road.
By bus: line 5 is available: Aosta - Aymavilles (Gressan town hall stop)