Rubicon, River in Italy
The Rubicon is historically significant as Julius Caesar crossed it in 49 BC, starting a civil war.
During Roman times, it was a small river that formed the boundary between Cisalpine Gaul to the north and Italy proper to the south.
The phrase 'crossing the Rubicon' has survived to refer to any individual or group committing itself irrevocably to a risky course of action.
It passes through the Italian province of Forlì-Cesena and into the Adriatic Sea.
Despite its historic significance, the exact location of the Rubicon river remains uncertain.
Location: Savignano sul Rubicone
Source: Wikimedia