The Stiftsbibliothek St. Gallen (Abbey Library of Saint Gall) is a marvelous Rococo structure constructed between 1758-67. Baroque was superseded by the Rococo style. When we went there we spent hours in awe, and completely forgot to eat lunch.
From Wikipedia: The library collection is the oldest in Switzerland, and is one of earliest and most important monastic libraries in the world. It holds 2,100 manuscripts dating back to the 8th through the 15th centuries, 1,650 incunabula (printed before 1500), and old printed books. The library holds almost 160,000 volumes, and most are available for public use. Books published before 1900 are to be read in a special reading room. The manuscript B of the Nibelungenlied is kept here.
It is not allowed to take photos because the old books cannot handle bright light. Even if you would ask visitors not to use flash many people still would leave the flash on, so their rule is understandable. I asked what the process is to get permission as a photographer to take photos. I met the person in charge and they were so kind to arrange short noticed a 30 minute window after the closure time at 5pm. I did many long exposures, naturally avoiding the flash light.
I processed a soft HDR photo from a RAW exposure, and carefully adjusted the curves and color balance.
-- © Peter Thoeny, CC BY-NC-SA 4.0, HDR, 1 RAW exposure, NEX-6, _DSC0917_hdr1sof2f