Nice little escape from the city
Definitely check out the Garden - it's one of my favorite parts of the city. In the spring it's covered in tulips (beautiful!) - during the summer it's a great place to enjoy some of the little greenery Boston has to offer. It's right in the heart of the city, bordered by the theater district, Downtown Crossing, and Beacon Hill. Take a ride on the swan boats, or just relax and people-watch. It's a wonderful little oasis from the city.