Cologne, the French say.
Germans call it Koln.
The ROMANS called it Colonia. It's OLD.
The big church is the Cathedral of the Three Holy Kings. It was built to house a casket containing purported remains of the three Magi (Persian Kings) who visited Jesus shortly after His birth. It is the finest German High Gothic construction in the world..... and VERY possibly one of Humanity's greatest affirmations of Faith. The inside is utterly incredible. It is still a working Church, though, so have respect. The old white columns just outside the main entrance are the remains of a Roman Temple, one of the few visible relics of the ancient border town, although there is a lot in the city Museum.
Coming up from the Ruhrgebeit, you cross the Hohenzollern Bridge with its huge equestrian statues of Kaiser Wilhelm II at either end. The statues were removed for safety during the Second War and the Bridge had a very large bomb planted precisely between its two biggest spans. I have seen a photograph of the Bridge, taken from a low-level Lanc just a few days after the shooting ended and it shows the Bridge and the bomb damage....... and the entire city in utter ruin, hardly anything more than 6 feet high, only this magnificent Cathedral rising above it all, apparently undamaged.
Get closer, though, and you can see the pock-marks in the Cathedral from the Hurribombers and Thunderbolts and Mitchells, but the fabric of the building was struck only once by a bomb and the damage was limited, although there is a sign inside telling of the "allierte Schreckflieger". Actually, hitting the Cathedral was a court-martial offense in our Air Force but people have forgotten that part.
With true Germanic thoroughness, every building in the city had a duplicate set of its complete construction plans, continually updated, in the City Archive, which was in an EOTW-proof vault. When the shooting stopped, this vault was opened and the city REBUILT COMPLETELY from the original plans. There is NOTHING in downtown Koln (except the Cathedral) which is as old as I am (I was born in 1944)..... yet it looks exactly like a 19th-Century German city..... because it ALSO is completely ORIGINAL. Fascinating tale, and so very true.
I visited there n 1976, just as they were welding up the final bullet-holes in the roof over the train platform, and you could pick out the .303-calibre and the .50-cal and the 20mm holes very clearly, each one chalked for the welders, up to about 16 feet. I guess they just painted over the higher ones. I had had a rough several days (blown engine on a BSA, endless unbudgetted expenses, a railway functionary with a Red Plastic Belt, a robbery and so forth) and I was thoroughly sick of Germany by that time, so I looked up at those holes and remembered that my Dad had built the aircraft which put them there..... and, very quietly, I said, "Thanks, Dad!"
But the Cathedral is a MUST. It's 200 yards from the railroad station, so you have no excuse. If you see NO other building in Europe, it is still a MUST.
You, too, can be in the presence of the Three Holy Kings.