In 2005, Pascal Sombardier discovered the largest natural arch in the Alps, Tour Isabelle or Tour Percée, with a span well over 90 feet (30 meters). He revealed the find to the world a year later in a book entitled Chartreuse Insolite, with a cover photo that triggered a passion for arch hunting across the region. In the following years, over 70 arches were added to the list in Chartreuse alone.

The Chartreuse Mountains, a limestone massif in France, is a reasonably small range but boasts some of the most beautiful arches in the Alps. Sombardier discovered the Miracle Arch in 2005 and provided the marvelous formation with its namesake. Since the two tracts of rock rest on each other by a very thin junction, they form a natural flying buttress.

Miracle Arch is the second largest arch in the mountain range, with a span of over 80 feet (25 meters). While located only a few hundred meters from the Tour Isabelle arch, this formation is harder to reach. Visitors must rappel down several cliffs, or ascend a narrow couloir and scale a few jagged rocks to reach this natural wonder.