This is one of the most famous natural bridges of the world. Located in the middle of a popular recreational area it is well known, a landmark used for orientation and as a meeting point. Here, at the upper end of the Ardeche gorge, is a campground and the starting point of the boat trips through the valley. The nearby village Vallon was named after the natural bridge, and other things too. There are restaurants, hotels, and camping grounds named Pont d'arc.
The genesis of this natural bridge is rather easy to understand. Originally the plain was drained by a subterranean river in a cave system, right where now the arc is. The cave became bigger and bigger, and because of the close surface the roof collapsed. Most parts of the cave soon formed huge dolines, then poljes with steep walls. The walls were softened by weathering and soon the former cave looked like a nice valley. Only one short part of the cave is still there, the arc itself. It stayed, most likely because the limestone here is a bit harder and thus resists weathering better than the limestone around.

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