1. Laon Cathedral - here I am sitting in empty nave. Laon wears the then-new Gothic style with such graceful & intellectual ease I wondered if all later Gothic a debasement. I'm not normally into perfection - but here it is.
This was a highlight of @EmilyGuerry & my tour of Germany two summers ago, in which we saw 16 cathedrals, 15 Abbey churches, & 13 UNESCO world heritage sites in 9 days.
I wrote about it for @C20Society: jstor.org/stable/24644446