Keystone (architecture)
Videos
A keystone is the wedge-shaped stone at the apex of a masonry arch or typically round-shaped one at the apex of a vault. In both cases it is the final piece placed during construction and locks all th
Dropped keystone at Colditz Castle
Keystone from the palazzo Borgazzi (Milan, Italy)
Keystone much enlarged for decorative effect, and carrying a coat of arms, Barcelona
The York Minster Chapter House rib-vault ceiling with central and peripheral keystones
Rib vault
Videos
A rib vault or ribbed vault is an architectural feature for covering a wide space, such as a church nave, composed of a framework of crossed or diagonal arched ribs. Variations were used in Roman arch
Romanesque rib vaulting, Peterborough Cathedral (begun 1118) south aisle
Gothic rib vaulting, Tours Cathedral, nave
Rib vaulted ceiling of Noyon Cathedral, one of the first Gothic cathedrals built in France
Rib vault from Villa Sette Bassi, Rome (c.150)