I have been to Mount Greylock many times. It is a beautiful place especially in the fall when the leaves have changed. The view is just magnificent and on a clear day one can see the Corning Tower in downtown Albany NY. There is a lodge there with a snack bar and a fireplace. One can also spend the night there, but reservations are recommended.

http://www.state.ma.us/dem/parks/mgry.htm

I remember the first time that I went up in the tower. I said to myself, "this is a lighthouse". After some investigating, I found out that it was originally supposed to have been built in Boston Harbor.
I told Tim Harrison about this structure a number of years ago and showed him some pictures of it. He did a couple of articles in the Lighthouse Digest about it. And now it is a collectible produced by Harbour Lights and it all started with a simple day trip to a mountain top.