Rubicon

The Rubicon (Latin: Rubicū, Italian: Rubicone) is a shallow river in northeastern Italy, about 80 kilometres long, running from the Apennine Mountains to the Adriatic Sea through the southern Emilia-Romagna region, between the towns of Rimini and Cesena. The Latin word rubico comes from the adjective "rubeus", meaning "red". The river was so named because its waters are colored red by mud deposits. It was key to protecting Rome from Civil War.