Microsoft Store
 

Keystone (architecture)


 

In architecture, a keystone is the stone at the top of an arch. It the supporting element for the entire arch— without it the arch would collapse.

Related Topics:
Architecture - Arch

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

the keystone was also the logo of the Pennsylvania Railroad a railroad that operated throughout the northeastern and midwestern United States.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~