Chess fans today may not recognize this decorated thimble-shaped object, but a recently discovered 800-year-old game piece from Norway is actually a knight.

At this factory in Amritsar, India, artisans carve the pieces for the official World Chess Championship sets. And the factory produces only 250 of them each year.

This Iranian chess set, created in the 12th century, features four stone rooks with two pointed horns each, representing horse-drawn chariots. The design is nearly identical to the "rook" figurine ...