When I started planning our trip, I came across a book called, Quiet Corners of Paris by Jean-Christophe Napias. My sweet in-laws sent it to me for Christmas and I am so glad they did. It highlights gardens, walkways and quiet spaces that you can visit (usually free of charge) and hear yourself think.
Although this trip was jam-packed, I knew that I could fit in this "quiet space" as it was near our hotel in the heart of Saint-Germain-des-Pres. The garden at Musee Eugene-Delacroix is a lovely spot where the crunch of your feet on the gravel is the only sound you hear.
I knew that the hustle-bustle of the Paris was just behind these walls, but the sound was dampened somehow. I sat for a moment in this garden and simply breathed.