Peaceful places to visit alone for a woman

I live near Medical College and am looking for calm and beautiful places I can visit during the day, where I can relax and unwind. Beaches are my favorite, but I’m open to other suggestions. I’d prefer spots I can explore and return from within 3 hours. Since I’ve never really gone out alone before, I’m trying to step out of my comfort zone. I’m on a gap year with plenty of free time, so I’d like to make it a habit to go out every day. Any recommendations?