This 121m-long former Benedictine abbey church, a Unesco World Heritage Site, mixes Romanesque elements from the mid-11th century (the worn but stunning nave and transept) with early Gothic features from the latter half of the 12th century (the choir, with a large triforium gallery and, way up top, tiny clerestory windows). Next door is the Musée St-Rémi.
The abbey church is named in honour of Bishop Remigius, who baptised Clovis and 3000 Frankish warriors in 498. The 12th-century-style chandelier has 96 candles, one for each year of the life of St Rémi, whose tomb (in the choir) is marked by a mausoleum from the mid-1600s.