Saint-Michel d'Aiguilhe stands on the most dramatic of Le Puy's volcanic needles — an 82-metre column of basalt that shoots straight up from the plain. The chapel at its summit was built in 962 and enlarged in the eleventh and twelfth centuries; it is a Romanesque building of extraordinary ingenuity, constructed to fit the irregular summit of a rock spike with no flat ground. The interior is tiny but contains some important medieval frescoes.
The climb involves 268 steps carved into the rock face, accessible from the base. At the top, the views over Le Puy and the surrounding volcanic plain are exceptional — you can see the cathedral on its own rock, the giant Virgin on a third plug, and the Velay plateau stretching to the horizon. The chapel is open to visitors most days; check the current hours as they vary by season.