The Getty is my absolute favorite place to reflect. I once spent a year going to the Getty alone one Saturday each month, bringing my journal, sometimes also a book, sketchpad, or camera. My monthly trips there became a deep source of rejuvenation, epiphany, and questioning the current state of my life. And every time I have returned since, it has continued to be that place for me.
Its beautiful gardens in particular are rife with picturesque little nooks for taking a seat and thinking.