The Abbey of Saint Gall was founded in the 7th century on the site of an Irish hermit's cell and grew over the following centuries into one of the great centres of European learning. The complex — cathedral, library, cloister, and dependent buildings — was designated a UNESCO World Heritage Site in 1983. It is the best-preserved example of Carolingian-era monastic planning in existence.
The twin-towered cathedral was rebuilt in the Baroque style between 1755 and 1766 and is an exuberant interior of plaster, gold, and fresco. The nave is enormous and the stucco decoration was carried out by the same workshops that worked on the great Bavarian and Austrian Baroque churches of the period. Entry to the cathedral is free; it remains an active place of worship.