page_title: Arch
section_title: Types of arches
hierarchical_section_title: Arch / Types of arches
caption_attribution_description: Deutsch: Double-O-Arch im Arches-Nationalpark im Südwesten der USAEnglish: Double-O-Arch in Arches National Park in Southwestern USAFrançais&#160;: Double-O-Arch, dans le Parc national des Arches, dans le sud-ouest de l'Utah (États-Unis). Čeština: Double-O-Arch v Národním parku Arches (USA)
context_page_description: An arch is an opening in a building that is curved on top to distribute the weight. The curved part can be round, like part of a circle, or pointed, like two parts of circles next to each other. Arches are often used where buildings are made of many small stones or bricks. The stone at the very top of the arch, called the keystone, keeps the rest of the arch stones from falling down. Arches can go over doorways and windows. Many bridges are arch bridges including ones made of steel. A series of arches is an arcade.
  Arches can be found in nature. These natural arches form through the erosion of cliffs.
context_section_description: Arches  can have many forms, but they can be sorted into three categories: circular, pointed and parabolic.
  Circular (rounded) arches were used by Romans. They used them in bridges, aqueducts, and large-scale (big) architecture.
  Pointed arches were most often used by builders of Gothic-style architecture. They used them because they produced less thrust at the base. This allowed the structures to be taller.
  Parabolic arches have the shape of a parabola. They are mostly used in bridges.
caption: A natural arch
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