Here are a few photos of the churches we visited.
Notre Dame, probably the most famous cathedral in the world, as you know experienced a fire not all that long ago, and reconstruction is on-going. We were only able, therefore, to see some of the outside, and even then some aspects were blocked by construction and security walls
St.-Chappelle church is just a short walk away from Notre Dame, a little church tucked in behind a (now) government building, so we got no photos of the outside. But inside...the most impressive display of stained glass I've ever seen anywhere:
The chapel at the Palace of Versailles was as opulent as every other room in the palace
At Provins the St-Quiriache church dominated the town
In Bayeux, Normandy, again the church could be seen from almost anywhere around, and inside was a pipe organ that took up most of the wall
In Frankfurt also, many church spires soared over the surrounding buildings