A hidden gem not too far from Boston is Walden Pond. The spot where Henry David Thoreau,
…went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived.
It’s a fantastic spot for a little walking, a lot of natural beauty, and hell, you might even learn something. Check it out if you ever get the chance.