The form of the coastline around Durdle Door is controlled by its geology—both by the contrasting hardnesses of the rocks, and by the local patterns of faults and folds.

[8] Around this part of the coast, nearly all of the limestone has been removed by sea erosion, whilst the remainder forms the small headland which includes the arch.

[10] As the coastline in this area is generally an eroding landscape, the cliffs are subject to occasional rockfalls and landslides; a particularly large slide occurred just to the east of Durdle Door in April 2013, destroying a part of the South West Coast Path.

[14] Similar names in the region include Durlston Bay and Durlston Head further east, where a coastal stack suggests the existence of an earlier arch, and the Thurlestone, an arched rock in the neighbouring county of Devon to the west.

[18] Dorset-born Arthur Moule, a friend of Thomas Hardy and missionary to China wrote these lines about Durdle Door for his 1879 book of poetry Songs of Heaven and home, written in a foreign Land:[19] Shall the tide thus ebb and flow forever?and for evermoreRave the wave and glance the ripple through therocks at Durdle Door?