Grassy Pond and Nagog Hill Conservation Lands are contiguous properties, each with its own self-contained trail system. Together the two properties contain 273 acres within which a more than 3-mile circuit can be made by using the 0.2-mile red connector between the two trail systems. This connector leads into the Nagog Hill Conservation Land directly across Nagog Hill Road from the main Grassy Pond parking lot.

Grassy Pond Conservation Land comprises diverse habitats and ecosystems. These include the pond and its associated wetlands, two small streams, a vernal pool, a boulder field within moist woodlands, a large meadow, and forest vegetation of white pine, hemlock, and northern hardwoods. The latter include white ash, red and white oak, and some beech. In the spring, the white blossoms of dogwood trees may be seen scattered through the woods. Mosses are abundant in this moist forest, covering many stones and tree stumps.

There are three entrances:

• Southwesterly side of Nagog Hill Road, 1.25 miles from Acton Center (Parking; Kiosk at end of meadow)
• Northeasterly side of Newtown Road, west of Lincoln Road (Parking; Kiosk along access trail)
• End of Willis Holden Drive, off Hammond Road via Samuel Parlin Drive

The AllTrails website has a description and map of a hike at Grassy Pond Conservation Area.