Guernica by Pablo Picasso.

Guernica, probably Picasso's most famous work, is also his most powerful political statement, painted in response to the Nazis' devastating casual bombing practice on the Basque town of Guernica during the Spanish Civil War.

Depicts the tragedies of war and the pain it causes individuals, particularly innocent civilians. This work has achieved monumental status, serving as a constant reminder of war's tragedies, an anti-war symbol, and an embodiment of peace. The painting was completed and quickly toured around the world, becoming famous and widely acclaimed. This tour contributed to bringing the Spanish Civil War to the attention of the world.