10 Dollars Brunelleschi Dome - 4 of 9

Part of a nine-coin architectural series issued by Niue, this piece commemorates Filippo Brunelleschi's dome for the Florence Cathedral — completed in 1436 after over a century of construction delays that had left the building roofless while engineers across Europe debated whether such a span was even possible. Brunelleschi solved the problem without centering, using a herringbone brick pattern and a double-shell construction technique he largely kept secret during his lifetime.

The dome remains the largest masonry dome ever built, a fact that has not changed in nearly six centuries.