The Terryville Waterwheel is a large composite wood and iron waterwheel of pitch-back configuration dating to 1851. The factory that it powered was destroyed about 1940, but the wheel occupies its original site on the west bank of the swift-flowing Pequabuck River in the Terryville section of the town of Plymouth. The wheel is protected by a shelter erected in 1956, the roof of which duplicates the curve of the waterwheel. - NRHP