Grand-Hornu.

Grand-Hornu is a striking collision of 19th-century industrial ambition and cutting-edge contemporary culture. Originally built between 1816 and 1830 as a Neoclassical "ideal city" for coal miners, this UNESCO World Heritage site is one of the world's best-preserved examples of functional urban planning. The monumental brick complex once housed a self-contained community complete with 450 homes and its own library; today, those vaulted halls and sprawling courtyards serve as a backdrop for two distinct institutions. The MACS focuses on international contemporary art, while the CID explores the intersection of design and innovation through experimental exhibitions. Wandering the site offers a rare spatial experience where the soot-stained history of the Industrial Revolution meets the clean lines of modern high-concept design, making it as much an architectural pilgrimage as an art destination.