An ashlar is a stone carved on several of its faces, generally in the shape of a parallelepiped, and which is part of the ashlar walls.[1]​.

The ashlars usually have a size and weight that requires them to be handled by machines, unlike the masonry, which, as its name indicates, is placed by hand..

When the ashlars are superimposed without a mortar, mortar or cement to join them, the resulting work is called dry ashlar..

They are generally taken from an elongated stone that has three parts: head, heart, and trunk or body.

The same material is also called ashlar, with which objects and sculptures have historically been made.[2]​.

Small or roughly carved ashlars are called sillarejos,[3] normally ashlars of different heights and lengths are used in the same work; They therefore form courses that are unequal in thickness.

In some volcanic regions, volcanic tuff has traditionally been used for construction, which is a light, porous, ignimbrite-type volcanic rock, formed by volcanic ash and pyroclastic minerals, which originated in violent eruptions with the expulsion of pyroclastic flows. In this case, both the blocks used in construction and the type of material are called ashlar, as is the case, for example, with the ashlar from Arequipa, in Peru.