Étretat's chalk cliffs were formed in the Cretaceous period, millions of years ago, when the region was covered by the sea. The cliffs consist of deposits of light-coloured calcareous marine organisms and skeletons of siliceous organisms. Subsequent movements of the Earth's crust pushed these deposits up and brought them to the surface. Erosion by sea, wind and frost formed the characteristic rock arches and needles in the sea.

The cliffs around Étretat seem perennial, yet are fragile and constantly changing: wind, tides, infiltration of rainwater, freezing and then thawing weaken them. As a result, landslides occur regularly and the cliffs crumble.

They have become the impressive rock formations that can be seen today, such as the Falaise d'Amont/Cliff of Amont (main image, PiP 1and 2), Falaise d'Aval/Cliff of Aval (PiP 3 and 4), Falaise la Manne Porte/Manne Porte Cliff (PiP 5) and the Aiguille Creuse/Hollow Needle (PiP 6 and 7).