Arches & Doorways Arches were used by the Persian, Harappan, Egyptian, Babylonian,Greek and Assyrian civilizations for underground structures such as drains and vaults, but the ancient Romans were the first to use them widely above ground although it is thought that Romans learned it from the Etruscans. The arch has been used in some bridges in China since the Sui dynasty and in tombs since the Han Dynasty.The so-called Roman arch is semicircular, and built from an odd number of arch bricks (called voussoirs). You need an odd number of bricks for there to be a capstone or keystone. This the top most stone in the arch.