3 Place Saint-Germain des Prés
Saint Germain des Prés is very, very old. It's "parts of it reminded me of the room where Indiana Jones chooses wisely and drinks from the Holy Grail" old.
The church still hosts concerts featuring Gregorian chant, because a single monk chanting was the musical style of the day when the church was rebuilt around the 11th and 12th centuries (it had to be rebuilt because the Vikings kept knocking it down). René Descartes, the person who said "I think, therefore I am" and invented much of algebra, is interred there. He died in 1650, when the current structure was already standing for 500 years.
But it's a beautiful, expansive portal into the past. It has the stillness of a place that has represented peace for centuries.
Well, there was the time during the Revolution when a store of saltpeter exploded and leveled what was left of the 1,200 year old abbey that used to surround the church. Other than that one time, very peaceful.
We went to a few medieval churches on this trip, but the sense of time and age here was uniquely awe-inspiring. Notre-Dame felt like walking into the spiritual heart of Paris. It was bustling, vivid, with soaring organ music during Mass. Saint-Étienne-du-Mont was powerful, bright white, and stately, almost like people in the old times knew what to expect of heaven.
It's dark inside Saint Germain des Prés, the silence is stifling, and the air around you feels thick with time. The frescoes and statues are worn with the passage of centuries. If the votive candles weren't lit and the parish school wasn't headed out for recess, you might think that you and about a dozen fellow tourists rediscovered something previously lost to the ages.
There's wisdom to be found in the silence there. You can feel something spiritual in sharing the space with others, knowing how many came before. It's nice to follow in their legacy. Maybe that's the whole caper with religion, why the big ones have all been around for so long. If hell is other people, maybe heaven is other times.