The work of Mathieu de Layens, this impressive building is typical of the Brabant Gothic style. Inside, behind the façade, note the Car d'Or (1779-81), a carriage in carved, gilded and painted wood which carries the reliquary of St Waltrude (patron saint of the town) through the streets every year on Trinity Sunday. The chancel boasts seven allegorical alabaster statues by Du Broeucq. Also of interest are the 16C-17C stained glass windows, the Flamboyant Gothic Les Féeries Notre-Dame altarpiece (first chapel on the right of the ambulatory), and the superb treasury.