On a small lane north of the main station lies St. Ursula, an impressive Romanesque church originally built around 1150 AD. While Cologne does have its fair share of churches, this one is significant: it is built upon an old Roman cemetery, and comes with the Goldene Kammer, the Golden Chamber.
According to legend, St. Ursula was a British princess travelling with an entourage of 11,000 virgins who followed her on a pilgrimage around Europe in the year 300, where they encountered heathen Huns and were all promptly slaughtered. So when during the construction of the church a Roman mass grave was discovered, church officials quickly claimed the dead as the remains of St. Ursula and her virgins, turning them all into relics and giving the church its name. Fast forward to 1643, when the church was renovated. Imperial privy councilor Johann Krane and his wife Verena Hegemihler became the founders of what is the Golden Chamber today, a place to display both the bones of the virgins and the growing relic collection of the church itself.
I am an atheist, but love to visit the chamber for both a bit of the thrill of seeing bones up close and the odd reminder that our time on earth is short. The four walls of the Golden Chamber are covered in bones arranged in design patterns or Latin words, and there are shrines and altars covered with more bones and skulls, most of them in elaborately made silver or gold relic holders. A fascinating place.