Cologne Cathedral, Germany: Cologne Cathedral is a cathedral in Cologne, North Rhine-Westphalia belonging to the Catholic Church. It is the seat of the Archbishop of Cologne and of the administration of the Archdiocese of Cologne. Wikipedia
Ms. Codex 1233 is a pretty amazing manuscript. Originally written in the early-to-mid 15th century, it was used continuously through the end of the 18th century. Written in Cologne and probably used by the canons in the Cologne Cathedral, this notated breviary (a liturgical book containing the canonical hours - daily prayers - with musical notation) includes notes and additions made up to 1794. It also includes splatters of candle wax and one page that got a little too close to a candle!