-Check out the U.S.S. Constitution, old iron sides, in the Charlestown Navy Yard. This is a short walk from the north end or a water shuttle from rose warf.

-Copley library in copley square is fairly cool, old architechure and some amazing marble work.

-Skywalk at the prudential building gets you to the top of the building for a fee. At night I reccommend going to the bar at the Top of the Hub rather than doing the skywalk. You don't pay the skywalk fee and you can sit and listen to jazz while having a drink. Don't bother with eating at the restaurant.

-Arnold Arboretum is a botanical graden type thing out on the green line by Arbor way (Jamaica Plain). Its just okay ordinarily, but you might catch some of the lilac exhibit at that point in the spring which is really nice if you like that.

-If you can't get into Fenway go to the Cask n Flagon, next best thing.

-Esplanade- nice area on the charles river where they often have free shows and movies in the spring summer. There is also a path that borders the river to walk or run on where you get good views of cambridge and all of the sail boats. You can rent kayaks for the Charles too which isn't bad.

-Many churches in the copley area and north end that you can tour if you like that.

-Newbury street is good to people watch and do some shopping, always interesting people and stores there.

-Harpoon brewery tours in South Boston are good, there is a Sam Adams one too by Stoney Brook on the orange line.

-Lots of concert venues if you like Indie or main stream. The Paradise, Middle East and Avalon are my favorites for cheap club shows with up and coming bands.