The capstone is the highest rock or mount of a structure. Often they have "doorways", the capstone would lock or wedge the rest of the rocks tightly together, giving strength, much like a wedge, when driven into a tight spot. The reverse side of a dollar bill denotes a single "eye" as the capstone of the pyramid, (also called a Pyramidion-stone). In an arch, the capstone, or sometimes called the keystone, holds the arch together.

An American stonehenge Georgia Guidestones has a capstone, atop all the other languages/stones, written in ancient languages. On each side of the capstone a different language is written including Sanskrit, Classical Greek, Egyptian Hieroglyphs and Babylonian cuneiform. These languages signify the past as the parent of the modern age.

Seven Ancient Wonders - The Book

In a book by Matthew Reilly, Seven Ancient Wonders, the Capstone to the Great Pyramid features magical powers. In the book, the capstone was broken up into seven pieces that were spread around the world, hidden in the Seven Ancient Wonders (hence the name of the book). Note: this book is entirely fiction.

See also

• Keystone