Millau Viaduct

The viaduct carries the A75 over the Tarn valley near Millau, opened in December 2004 after the old route through the town became a notorious summer bottleneck. Michel Virlogeux engineered it and Norman Foster designed it: a cable-stayed deck two thousand four hundred and sixty metres long on seven piers, with the tallest mast reaching three hundred and forty-three metres above the base, making it the tallest bridge in the world by structural height. The deck sits about two hundred and seventy metres above the river. It is often photographed with cloud filling the valley beneath it and the roadway apparently floating.

What you actually see

• The scale - a 343-metre mast and a deck 270 metres above the river.
• The valley viewpoints - laybys and belvederes giving the full span.
• The cloud effect - mist filling the valley below the deck on some mornings.
• The visitor area - an exhibition on the design and construction below the bridge.

When to go

April to October; autumn and winter mornings give the best chance of valley cloud. Crossing costs a toll that rises in summer. Viewpoints from the D992 and the belvedere are free.

Honest expectations

Crossing it gives little sense of the height because parapets block the view; the bridge is better seen from below. Toll rates increase in peak season. The visitor centre is modest.

Nearby

The Gorges du Tarn lie northeast; Roquefort is south.