Memorial Day Fun: A Walk around Walden Pond

Today Jeff and I took an early morning walk at Walden Pond, near Concord, MA.  This is the location of Henry David Thoreau's book, Walden.  We walked 1.7 miles, enjoying the beautiful and quiet scenery.  Also, if anyone can tell me what the flower is, I would greatly appreciate it, I have googled it, but I have not figured out what it is!