France is chock-full of palaces, but there’s one – Palais Ideal – that stands out above the rest as a work of art and devotion. Ferdinand Cheval, a French postman with no formal architectural or artistic training, spent 33 years building this extraordinary structure by cementing together oddly-shaped rocks that he found along his mail route.

Construction on the palace began in 1879 and was completed in 1912. After stumbling on a strange stone that inspired his dream, Cheval began walking his 18-mile mail route with a wheelbarrow so he could collect other strange rocks and pebbles.

The Palace Ideal is located in Hauterives, a town in southeastern France. It is open almost all year for visits, and also often serves as a venue for extraordinary concerts and art exhibitions. If you’re traveling to France, but this amazing work of DIY outsider art on your list!