Arch

The **arch** is a curved structure that has been used for construction since ancient times (however, not all ancient civilizations used it). With this new element, people discovered brand new possibilities: the **beam** was not the major structure anymore. The arch not only bears great loads with a major span between posts. It also creates a wide range of beautiful forms and designs.

The arch has several parts or components. The most important are the **key stone** (the one that bears almost the whole load of the structure and is responsible for its balance), the **posts**, the **capital** and the **vossuoirs**. The arch has also certain measures based on the **display** of the different parts: we have the **crown**, the **span** and the **rise**, among others.

There are also different types of arches: the **round arch**, the **ogee arch**, the **horseshoe arch**, the **three-foiled cusped arch**, the **lancet arch** and the **Tudor arch**, among many others. There`s a special type of arch, the parabolic arch, that was used very often by Antonio Gaudi. It`s a very complex structure that creates beautiful spaces, but is the most difficult arch to be built.