Italian River Famously Crossed by Julius Caesar

This page is the CodyCross answer for the clue below from Space Exploration, Group 909, Puzzle 1 (Simulated Flight).

Question is: Italian River Famously Crossed by Julius Caesar

and the answer is: RUBICON

Word Meaning:

RUBICON — A limit that when surpassed cannot be returned from, or an action that when taken cannot be reversed.

Definitions from Wiktionary.