The Lion Monument is a poignant sculpture carved directly into a natural sandstone cliff, commemorating the Swiss Guards who fell defending King Louis XVI during the French Revolution in 1792. Designed by Danish sculptor Bertel Thorvaldsen and carved between 1820 and 1821, Mark Twain famously called it 'the most mournful and moving piece of stone in the world.' The dying lion shields a coat of arms bearing the French royal emblem, symbolizing loyalty and bravery.