The Great Door (La Manneporte)

La Manneporte is so colossal that renowned French writer Guy de Maupassant famously compared it to a 'Gothic portal' capable of letting a fully-rigged sailing ship pass through with all its sails unfurled. This vivid description from his 1883 short story 'Le Horla' helped cement the arch's legendary status in French literature and continues to captivate visitors who try to imagine this spectacular sight.

Contrary to popular belief, the arch was not carved solely by the relentless pounding of ocean waves. Geological research has revealed that La Manneporte is actually the remnant of an ancient underground river system - a karst gallery that ran parallel to the coastline millions of years ago. The sea later exposed and widened this prehistoric tunnel, creating the dramatic natural arch we see today.

Impressionist master Claude Monet was so obsessed with painting La Manneporte that he created over a dozen works featuring the arch during his visits to Etretat in 1883, 1885, and 1886. He would often work on multiple canvases simultaneously, capturing the changing light at different times of day - a technique that helped define the Impressionist movement and made the Etretat cliffs world-famous.

The chalk cliffs of La Manneporte contain an extraordinary geological timeline spanning 85 to 93 million years. The white rock is composed of countless microscopic coccoliths - calcium carbonate plates from ancient algae - that accumulated at the bottom of a warm, shallow sea during the Cretaceous period when dinosaurs still roamed the Earth. Dark horizontal bands of flint visible in the cliff face represent layers of silica-rich organisms that lived during this prehistoric era.