Forty Caves


A geology enthusiast’s playground, the trails of Forty Caves wind through enormous boulders and outcroppings. Hikers will enjoy glimpses of a steep drop-off with tumbled rocks that create numerous crevices and give the area its name. North Brook riffles and gurgles over and under stones through a cool hemlock forest, and numerous vernal pools provide a chorus in spring.

Full Description

The Forty Caves conservation area includes lands owned by the Town of Berlin, the Town of Clinton, and SVT.

Striking features catch your eye as you explore Forty Caves.  Trails narrow to squeeze between rock outcroppings. Glacial erratics punctuate the woodlands. Granitic gneiss spotted with feldspar crystals provide evidence that the glacier plucked some of these boulders from cliffs that lie just north of the conservation area.

  • North Brook rattles and gurgles beside you along the trail as it slips under a flat slab of rock. It finally widens into a quiet pool with banks that invite a picnic stop, as the brook continues onto the Assabet River.
  • Steep cliffs in Berlin's portion of the conservation area overlook a marsh and stream that makes its way to North Brook. 
  • You’ll notice steep drops alongside the trail. A view from the orange trail near Allen Road looks down toward the namesake of the conservation area—caves created by tumbled boulders and rock slabs that lean together.
  • The geology of this site is spectacular. The Clinton-Newbury fault is visible at several points. The rock is tightly folded and crinkly, different from the granite gneiss found elsewhere in the conservation area.
  • Local legend holds that the smooth, round depressions in the rock at Forty Caves once held quartz that Native Americans used for spear points. They popped the quartz nodules out of the surrounding rock with a combination of heat and cold. 
  • The Forty Caves conservation area protects habitat for two endangered species: Blanding’s turtle and marbled salamander.

​Trails on the property are accessible from parking areas on Allen Road in Berlin and on Francis Street in Clinton.


For Allen Road in Berlin:

For directions from your location, see Google Maps.

From the center of Berlin, head west on MA-62W (West Street), approximately 1.4 miles. Turn right on West Street and proceed approximately 0.4 mile. Turn right onto Allen Road and follow approximately 0.6 mile to a parking area on the right. The parking area is marked with a sign for Forty Caves, and the orange trail proceeds to your right from the trailhead kiosk.

For Francis Street in Clinton:

With mapping software, search for this address: 
Francis Street, Clinton, MA

For directions from your location, see Google Maps.

From the intersection of Mechanic Street and Chestnut Street in Clinton, proceed south on Chestnut Street 0.3 mile and turn left on Cameron Street. After 0.2 mile take a slight left on Oak Street. After 0.1 mile bear right onto Chace Street and proceed approximately 0.5 mile before turning right onto Francis Street. Francis Street is a small dirt road. You will see a Forty Caves sign on your right approximately 200' down the road. Turn right at the sign, and find parking ahead on your left. The orange trail proceeds from the kiosk.

Nearby Nature Sightings

A red squirrel at Forty Caves Conservation Area in Berlin, photographed by Gail Sartori.
Gail Sartori photographed this red squirrel at Forty Caves Conservation Area in Berlin.
Mainstone Farm Trail. Photo by SVT.
Kent Fox used his automatically triggered wildlife camera to record this video of a porcupine at Forty Caves in Berlin.
A marbled salamander at Forty Caves Conservation Area in Berlin, photographed by Karin Paquin.
Karin Paquin photographed this marbled salamander at SVT's Forty Caves Conservation Area in Berlin.