Basilique Notre Dame du Port Clermont-Ferrand

This architectural gem has all the key elements of a Romanesque church: semi-circular arches, a bulky silhouette and a broad headpiece. But its distinctive decorations set it apart, and strengthened the case for granting it Unesco World Heritage status in 1998. Floral and geometric patterns of black volcanic stone are smoothly set in its peachy sandstone. Its exterior playfully combines neoclassical columns, terracotta tiles and medieval reliefs. The exterior is best admired from the belvédère; follow signs across the street.