This well-preserved Romanesque edifice is built from golden and rose-hued stonework up to the tip of the octogonal bell tower. Entry is free, but it’s worth the additional charge to explore the ambulatory, where marble statues stare from alcoves in the brick walls. The tomb of the basilica’s namesake St Sernin (also known as St Saturnin) has pride of place: he was Toulouse’s first bishop and met a gruesome end when pagan priests tied him to a bull.
Down in the crypt (accessed from the ambulatory), you can tiptoe among the shadowy rib vaults to view reliquaries containing venerable bones from the likes of St Papoul, another southern French martyr. It also houses various ceremonial objects. Entry hours to the ambulatory and crypt are reduced from October to May (10am to noon and 2pm to 5.30pm).