A volcanic plug, also called a volcanic neck, is a volcanic landform created when magma hardens within a vent on an active volcano. A natural monolith is a mountain or large rock formation consisting of a single massive stone. Both types of these geological structures are similar in that they are often steeply rising above the surrounding terrain. The unusual appearance and the buildings which are often located on these structures, amaze visitors and attract them to come back again.

01. Saint Michel d'Aiguilhe — France



The Chapel of Saint-Michel d'Aiguilhe is a fascinating little pilgrimage chapel perched atop a rocky needle of volcanic formation jutting dramatically high into the sky, at a place near Le Puy-en-Velay in France.

 The chapel was built in 962, to celebrate the return of Saint James from the pilgrimage. In 1429 the mother of Joan of Arc, Isabelle Romée, was said to have come to the site to pray.

The rock was first climbed officially on July 1954. In 2006, Luis Villegas, Pedro Nel Ramírez and Ramón Díaz climbed the rock in a five-day endeavor, using sticks that were fixed against the rock's wall. A new species of plant was found on the top of the rock, subsequently named Pitcairma heterophila by a German scientist.