Bancroft's Castle, Groton Fire Tower, MA

• 4-star hike
• 1½ mile out-and-back
• Easy | Gain 180 feet
• Groton, MA | Northeast Region
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A multi-story circular tower constructed from mortar-bound, irregular fieldstones and rounded cobblestones of varying sizes and earth tones. The structure features thick, rustic masonry walls punctured by multiple open rectangular window voids across its lower and upper levels, leading up to an overhanging upper section supported by stone corbels and topped with a crenellated parapet wall. A slender flagpole extends vertically from the center of the tower's open roof, while low, matching fieldstone wall fragments extend outward from the base into the surrounding terrain.

Views of Bancroft's Castle tower through the trees.

Rising above the trees on Gibbet Hill in Groton, Massachusetts, a stone tower looks like the remains of a medieval fortress. It isn't. In 1906, Groton native General William Bancroft, a former mayor of Cambridge, began building a retirement estate on the hill. He named it Shawfieldmont and planned a grand mansion alongside a modest bungalow, but ran out of money before the larger house could be built.

The project was abandoned, but the bungalow remained and took on a second life. It was repurposed as a sanitarium in 1918 and later served as a social hall for the Groton Hunt Club through the 1930s. A Fourth of July firecracker accident in 1932 burned down much of the structure, leaving behind the stone framework that locals now call "Bancroft's Castle."

The trail begins at the large parking lot for the Gibbet Hill Grill, just outside Groton center, making this a welcome short hike after an indulgent meal at the restaurant. From the lot, the path crosses rolling fields, passes a tranquil pond, and enters a shaded stretch of woods parallel to Lowell Road as it ascends toward the castle.

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⬤ 4★ Bancroft Castle & Gibbet Hill Fire Tower 1.5 mi out & back, easy, gain 180 ft
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P Free parking

While some hikers attempt to shorten the trek by parking in roadside turnouts along Lowell Road closer to the hill, these spots are unofficial and vehicles are reportedly ticketed. Parking at the Gibbet Hill Grill remains the safer, hassle-free option for visitors.

The castle ruins sit about 0.4 miles from the trailhead, where visitors can explore the grounds and step inside parts of the remaining stone structure, including the base of the tower. Just beyond the castle, the trail climbs further uphill, opening to westerly views of sweeping pastureland and distant mountains. Satisfied with the vista, many hikers turn back here, often unaware that another landmark lies further along the path.

Continuing past the overlook leads visitors to the Groton Fire Tower, a 68-foot steel structure at the summit of Gibbet Hill that is still staffed during fire season. Because foot traffic thins out past the castle, it is easy to miss if you don't know it's there. During our visit, we were lucky enough to find the cabin occupied. After calling up to the lookout operator, we were invited up to chat and enjoy 360-degree views over northern Massachusetts, a far wider and higher vantage point than anything visible from the castle grounds below.