Coordinates: 51°37′19″N 0°39′18″W / 51.622°N 0.655°W / 51.622; -0.655
Knotty Green, once a rural hamlet in the Buckinghamshire Chiltern Hills. It is characterised by large houses set in their own extensive grounds and though it remains within the civil parish of Penn today it has become contiguous with the market town of Beaconsfield. .
The centre of the old hamlet is still identifiable at the junction of Penn Road and Forty Green Road where there remains a remnant of the old green from which the hamlet took part of its name. The name of the hamlet can be traced back to the 13th century. Knotty Green, or Nattuc as it was called in 1222, takes its name from Old English nattuc (rough grass of tussocks) that grew on the green.
There are several surviving buildings built in the 15th and 16th centuries, including timber-framed hall house Baylins Farm (or Beelings Manor) dating back to 1450. Opposite the cricket pitch stands Hutchins Barn, a 16th-century timbered house with a minstrels gallery. Eghams Farm, built in Tudor times, is a private residence and stands on a path leading to Hogback Wood.