Bartholomew's Cobble is at 105 Weatogue Rd. The 329-acre reservation on the Housatonic River is named for two rocky knolls consisting mostly of limestone and marble. A wide variety of fern, wildflower and bird species can be seen.
The preserve has a natural history museum and visitor center staffed by a naturalist and also boasts 5 miles of trails, including one path that brings hikers to the summit of 1,000-foot Hurlburt's Hill. Another trail leads to nearby Ashley House.