The best cycling routes around Montjaux

Built between 1818 and 1821, the Lerouge bridge became one of the main structures for crossing the Tarn in Millau. It replaced the Pont Vieux, several arches of which had been destroyed by a flood in 1758, leaving the town without a permanent bridge for over sixty years. During this long period, crossing the Tarn was mainly done by ferry. The project was launched on the initiative of the prefect of Aveyron, d’Estourmel. The plans were drawn up by Pierre-Jacques Le Rouge, an engineer for the district. The first stone was laid on June 20, 1818, and the bridge was opened to traffic in January 1821. Its name therefore comes from its designer, not from the color of its stones. A curious detail: its construction was largely financed by private individuals, and a toll was collected until 1875. This tax even caused tensions with the inhabitants of Creissels, some of whom continued to cross the Tarn on foot or by boat to avoid paying it.

Perched at an altitude of about 730 meters, the Cap de Coste viewpoint overlooks the eastern end of the Boundoulaou cirque. It reveals a vast panorama of the Millau basin and its surrounding massifs. To the left, the easily recognizable Millau Viaduct spans the Tarn valley to connect the Larzac to the Causse Rouge. Further to the right stretches the latter: a large limestone plateau whose undulations dominate the valley. Then, the Puech d’Andan stands out with its wooded silhouette, cut in two by a clear central notch. Finally, further away, the Pouncho d’Agast, an emblematic relief of the Causse Noir, is easily recognized by its profile like a true limestone pyramid.

Perché at an altitude of approximately 730 meters, the Cap de Coste viewpoint overlooks the eastern end of the Boundoulaou cirque. It reveals a vast panorama of the Millau basin and its surrounding massifs. To the left, the easily recognizable Millau Viaduct spans the Tarn valley, connecting the Larzac to the Causse Rouge. Further to the right stretches the latter: a large limestone plateau whose undulations dominate the valley. Then, the Puech d’Andan stands out with its wooded silhouette, cut in two by a clear central notch. Finally, further away, the Pouncho d’Agast, an emblematic relief of the Causse Noir, is easily recognized by its profile like a true limestone pyramid.

From this switchback on the road to Labro, the Larzac plateau suddenly opens up to reveal the spectacular cirque of Saint-Geniez-de-Bertrand. This has been progressively formed by the erosion of the limestone series that make up the Larzac. The water, by infiltrating the fractures in the limestone, gradually dissolves the rock and circulates at depth before emerging at the foot of the slopes. This underground action, associated with runoff and valley erosion, causes a progressive retreat of the cliffs and slopes: this is the phenomenon of regressive erosion. Over time, the limestone reliefs recede towards the interior of the plateau and a vast indentation forms, giving birth to the cirque.

A small cultivated garden, a mini-greenhouse and two donkeys at liberty: a bucolic and unexpected scene by the greenway.

From this point at the foot of the structure, the regular succession of piers and guyed pylons can be particularly well distinguished. The deck, 2,460 m long, crosses the valley at a height of approximately 270 m above the Tarn. Pier P2, the tallest, culminates at 245 m, while the assembly formed by the pier and its pylon reaches 343 m: a height greater than that of the Eiffel Tower. This perspective also recalls the technical feat that the construction of the viaduct represented. The metal deck was assembled in sections from either side of the valley, then progressively launched across the void. The joining of the two parts was carried out on May 28, 2004, 268 m above the Tarn, before the official inauguration a few months later. An interesting detail can be discerned here: despite its exceptional dimensions, the structure appears remarkably light. This impression is not accidental. The viaduct was specifically designed to blend into the valley by limiting the visual impact of its structure, with a very slender deck and piers that branch out in a "Y" shape.

From the greenway, the Millau Viaduct is revealed from a particularly spectacular angle! One becomes aware of the extraordinary dimensions of the structure. Built between 2001 and 2004, the viaduct crosses the Tarn valley over 2,460 m and connects the Causse Rouge to the north with the Causse du Larzac to the south. Its metal deck, approximately 32 m wide, rests on seven concrete piers extended by seven cable-stayed pylons. At its highest point, the entire structure reaches 343 m above the ground; the deck is up to about 270 m above the Tarn. Designed by engineer Michel Virlogeux and British architect Sir Norman Foster, the viaduct combines a very slender metal structure with piers whose "Y" shape helps to visually lighten the whole. The deck was manufactured in metal elements and then gradually launched from both ends of the valley. The joining of the two parts was finally carried out on May 28, 2004, at 268 m above the Tarn.

Absolutely worth seeing - view it from below and definitely join the architecture tour.