Natural arch

Most natural arches are formed from narrow fins and sea stacks composed of sandstone or limestone with steep, often vertical, cliff faces.

Good examples of this type of arch are the Durdle Door and Stair Hole near Lulworth Cove on Dorset's Jurassic Coast in south England.

Pothole arches form by chemical weathering as water collects in natural depressions and eventually cuts through to the layer below.

One example of this was the double-arched Victorian coastal rock formation, London Bridge, which lost an arch after storms increased erosion.

[7] Moon Hill in Yangshuo, Guizhou Province, China, is an example of an arch formed by the remnant of a karst limestone cave.

In a few places in the world, natural arches are utilized by humans as transportation bridges with highways or railroads running across them.

[8] The second, a weather-eroded sandstone arch with a dirt road on top, is on the edge of Natural Bridge State Park in Kentucky.

[9] The railroad from Lima, Peru crosses the Rio Yauli on a natural bridge near kilometer 214.2 as it approaches the city of La Oroya.

Delicate Arch in Arches National Park , Utah , United States
The Great Arch, Tabuk Province, Saudi Arabia
The Azure Window , Malta , before it collapsed in 2017
Metate Arch, Devils Garden (GSENM) , a very thin arch near the end of its life
A topographic map of Coyote Natural Bridge in Utah shows how the meandering Coyote Gulch carved a shorter route through the rock under the arch. The old riverbed is now higher than the present water level.
Natural Bridge , Virginia
Natural arches in the La Cathedrale formation of Tadrart Rouge range, Algeria
Hole-in-the-Wall
Natural Arch , Tirumala , India
Arch in Timna Valley Park, Negev Desert, Israel
The arches at Marinha Beach , Caramujeira, Lagoa, Algarve , Portugal
Es Pontàs is a natural arch on the coast of Mallorca , Spain
Durdle Door , Dorset, the United Kingdom
Little Prerast in eastern Serbia
Percé Rock , Quebec , Canada
The Arch of Cabo San Lucas , Mexico
Holei Sea Arch , Hawaii Volcanoes National Park , Hawaii , United States
Landscape Arch , Utah , United States – one of the longest natural arches in the world [ 16 ]
Rainbow Bridge , Utah, a natural bridge formed by a meandering watercourse
"The Hole in the Rock” on Piercy Island , Cape Brett , New Zealand
London Bridge , Victoria , Australia, before its partial collapse in 1990
Stone arch at Pedra Furada , Piauí , Brazil
Pedra Furada , Santa Catarina , Brazil