The Golden Chamber, or Goldene Kammer, of the church contains the alleged remains of St. Ursula and her 11,000 virgins who are said to have been killed by the Huns, possibly around the time of the Battle of the Catalaunian Plains.
The walls of the Golden Chamber are covered in bones arranged in designs and/or letters along with relic skulls. The exact number of people whose remains are in the Golden Chamber remains ambiguous but the number of skulls in the reliquary is greater than 11 and less than 11,000. These remains were found in 1106 in a mass grave and were assumed to be those of the legend of St. Ursula and the 11,000 virgins. Therefore, the church constructed the Golden Chamber to house the bones. The bones themselves are neatly arranged in "zigzags and swirls and even in the shapes of Latin words."[3]
Heinz Firmenich: St. Ursula und die Maria-Ablaß-Kapelle in Köln. Rheinischer Verein für Denkmalpflege und Landschaftsschutz, Köln 1976, ISBN3-88094-150-5