I'm going with my cousin (who is 19) to the Red Sox game on July 30th. He has never been to Boston before, and wanted to go a couple of hours early before the game at 7PM. We are taking the T in from Riverside.

I know there is a lot of things to do in Boston, I've been there MANY times. I just need some guidance with something to do with my cousin. Looking for something he'll be interested in, easily accessible on the T, and somewhat inexpensive.

Is something like going to the top of the Prudential something good? Duck tours maybe?