The Valère Basilica is the single most extraordinary thing in Sion, and arguably one of the most unusual churches in Europe. Built between the 11th and 15th centuries, it is a fortified church — essentially a small castle with a church inside it — perched on a steep rocky hill that rises directly from the valley floor. The walls, towers, and gates belong to the fortress; within them, the church is a world apart.
The basilica's interior contains the world's oldest playable pipe organ, dating from around 1390 to 1435. The instrument is still played during summer concerts, and hearing medieval music performed on a 600-year-old organ inside a fortress-church on a rock above a Swiss wine valley is one of those experiences that stays with you. The church itself has carved choir stalls, late-medieval frescoes, and an atmosphere of considerable antiquity. The climb up from the town takes about 20 minutes on foot and is fully worth the effort.
story: "The Valère organ's mechanical action dates to around 1435, making it the world's oldest functioning pipe organ. When it was rediscovered and restored in the 20th century, musicologists realised they were hearing the sound of the medieval church exactly as it was meant to be heard — something almost no instrument in Europe can offer."