Church used for coronation-free entry

This is a place one that caught my eyes from far from outside, used for previous coronation of emperors. It is one with free entry, where one can visit and really admire the artwork and sculpture inside the church. of note, one interesting thing is that it also got the unique stained walls seen in churches of europe and do not miss out the golden themed decorations as well. located at Domplatz 1, 60311 Frankfurt am Main, Germany