Keystone - Architectural elements

A keystone, or a keystone arch, is an architectural element used in the construction of vaults and arches. It is a central stone placed at the top of the arch or vault, where the voussoirs or structural elements converge.

The keystone is typically of decorative shape, carved or adorned, and it may have a structural role in supporting the weight of the vault.

Keystones can have different shapes and patterns, ranging from simple reliefs to intricate sculptures depicting human figures, floral motifs, or specific symbols. They have been used since antiquity and continue to be employed in contemporary architecture to