At the end of the 19th century, Joseph Ferdinand Cheval, is a simple postman who travels every day along the Drôme, from village to village. Alone, he is upset when he meets the woman of his life, Philomena. From their union Alice was born. For this child he loves more than anything, Cheval then throws himself into a crazy gamble: to build her with his own hands, an incredible palace. Never spared by the ordeals of life, this ordinary man will not give up and will devote 33 years to build an extraordinary work: "The Ideal Palace".