Alex Z.
Yelp
This place is pretty amazing. It's the tallest mountain in Massachussets, and the only one to have a substantial amount of boreal forest (Taiga) around the summit. There is also a much more extensive area of mixed forest that goes considerably farther down the mountain. The unique ecology of this mountain is a function of its microclimate--it is easily 10 (or much more) degrees F cooler at the top, so this is a great place to come on a hot summer day. If you come in spring or fall, and want to do the whole hike, though, be warned...it can get much, much colder at the top. The weather at the top can be considerably more unpredictable too (think wind, snow, rain). If it's already cool at the bottom, bring extra clothing, and even if it's dry below, be open to the possibility of precipitation at the top.
If you're into hiking, there are lots of trails, including both the trail to the summit, and a whole variety of side trails. The Appalachian trail also runs through this area.
If you're into birdwatching, this place is a goldmine. Expect to find such unusual species as breeding blackpoll warbler (only found at the very top, I think), blackburnian warbler (which can be found a bit lower down), yellow-rumped warbler, winter wren, purple finch, and a whole bunch of other species that do not as commonly breed at lower altitudes. At one point I stepped out of the car and heard, in very little time at all, black-throated blue, black-throated green, worm-eating, and blackburnian warblers, all in a single spot, with excellent viewing opportunties provided by the mixed and partly open forest. And this was in July!
The road to the summit has recently been repaved. It is not only open, but it is in excellent shape, and it is a very easy drive. If you're worried about a treacherous climb in your car, stop worrying, because this is about as easy as it gets for a mountain of this height in a state park.
At the top, there's a monument, and a little lodge and restaurant. The restaurant serves surprisingly good food at a reasonable price too.