Years ago when I visited Paris, Notre-Dame was the place everyone had to see!
I learned then that nearby Sainte-Chapelle was the hidden gem because very few knew about it and it wasn't part of the tours.
Today it's a different story. With Notre-Dame closed for repairs, Sainte-Chapelle has become a huge tourist attraction. This is still a must-see, but now you really need to get timed tickets online or get there early in the morning. Be prepared to wait! ☹️
Sainte-Chapelle is still a gem to see!
Now you enter first into the lower level which is gorgeous despite the reconstruction.
Be prepared to climb a spiral staircase to get to the main level. It's worth the effort!