The Chaîne des Puys-Limagne fault
It is one of the most recent additions to UNESCO's World Heritage—but not the least important! Stretching over some 32 km (20 miles) long and 4 km (2.5 miles) wide, the Chaîne des Puys-Limagne fault in Auvergne is a tectonic hotspot, a true witness of this fracture of the earth's crust, which led to the formation of this alignment of 80 volcanoes. The word puy is a regional term for a volcanic hill, which dot Auvergne.
This breathtaking landscape that can be observed in full length by climbing to the top of the Puy de Dôme, the highest point of the Chaîne des Puys, at 1,465 m (4,806 feet). From up there, you can admire this series of volcanoes with various shapes: cones like Puy Pariou; domes, like the famous Puy de Dôme; or maars, shallow craters which form when water comes into contact with magma, like the narse d'Espinasse or the Beaunit maar.
The basilica of Notre-Dame-du-Port in Clermont-Ferrand
This 12th-century Romanesque church has been a UNESCO World Heritage Site for more than 20 years as part of the "Routes of Santiago de Compostela in France ." Less known than the emblematic Clermont-Ferrand Cathedral, which is entirely made of Volvic lava stone, the basilica more than worth a visit.
While this Romanesque monument was built in arkose, a sandstone with a warm hue formerly quarried from Montpeyroux, you still find certain elements of Volvic lava stone. This is particularly the case with the mosaics surrounding the apse, and one of the bell towers rebuilt in the 19th century before the basilica was included in the inventory of historic monuments.
You must admire its portal carved with scenes from Christ's childhood, its pyramidal apse decorated with rosettes, or its 250 sculpted Romanesque chapters. And don't forget to take a look at the works of art it contains, like a statue of the Virgin nursing or even The Annunciation, by Philippe de Champaigne.
Cathedral of Le Puy-en-Velay
Perched at the top of the basalt rock overlooking the city, the Cathedral of Le Puy-en-Velay watches over its inhabitants.
Extended over the centuries to accommodate the growing number of pilgrims en route to Santiago de Compostela, this sanctuary dedicated to the worship of the Virgin has made good use of the difference in height to spread out on the top of Mount Anis. You can reach it by climbing the imposing 100-step staircase, at the top of which stands the facade of the building with alternating dark and light archstones or its mosaics.
People come here to admire the "Black" Virgin of Le Puy, a replica of the original statue brought from the East by Saint-Louis in 1254, as well as the murals and other frescoes decorating the monument.
Another must-see is the cloister and its machicolation building, symbol of the power of the religious community that reigned between these walls.