Pompous yet majestic, the Italian Renaissance–style former royal court church (1905) does triple duty as house of worship, museum and concert hall. Inside it's gilt to the hilt and outfitted with a lavish marble-and-onyx altar, a 7269-pipe Sauer organ and elaborate royal sarcophagi. Climb up the 267 steps to the gallery for glorious city views.
For more dead royals, albeit in less extravagant coffins, drop below to the crypt. Skip the cathedral museum unless you’re interested in the building’s construction. The sanctuary has great acoustics and is often used for classical concerts, sometimes played on the famous Sauer organ. Multilanguage audioguides for €3.