4. Fountain
Marcel Duchamp’s Fountain shook the art world by turning a simple ceramic urinal on its back and calling it art. In 1917, this everyday object challenged the belief that art must be skillfully handcrafted, sparking fierce debates about what truly defines art. More than a century later, Fountain remains a revolutionary symbol of conceptual art, proving that sometimes, the idea behind a piece is far more powerful than the object itself.