This is an 1,800 acre park covering area in Meriden, Berlin and Southington. It is known for Castle Craig, a tower given as a gift, along with the entire park, to the town of Meriden around 1900 by Walter Hubbard. 

There is lots of gnarly geology in here. The park is characterized by a long ridge. The stone commonly has a feature of protruding veins that is distinctive of the area and maybe most pronounced at this park. I think there are many bouldering areas that will be added here, eventually.

Take exit 4 from I-691 and go toward downtown on Main St (it's a left off the offramp if you were on west-bound and right if you were on east-bound). Head downhill about 1/2 mile and the park entrance will be on the left. 

You can park at the trailhead at the back of the pond area, which is good if you want to take the pedestrian overpass to the west side of the park.

You can also park in the main parking area there, which is good for accessing the east side of the park and the road that goes around the reservoir to the back of the park.