Two post mill mounds 560m and 660m north west of St John the Baptist's Church


Heritage Category: Scheduled Monument

List Entry Number: 1020123

Date first listed: 30-Nov-1925

Date of most recent amendment: 18-Sep-2001


Ordnance survey map of Two post mill mounds 560m and 660m north west of St John the Baptist's Church
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The building or site itself may lie within the boundary of more than one authority.

County: Cambridgeshire

District: Huntingdonshire (District Authority)

Parish: Bythorn and Keyston

National Grid Reference: TL 03832 75831, TL 03920 75794


Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

Post mills were the form of windmills in the medieval period in which the wooden superstructure rotated about a central vertical post. The central post was mounted on cross timbers which were stabilised by being set into a mound. This mound might be newly built but earlier mounds were also frequently reused. The whole superstructure of such a mill was rotated to face into the wind by pushing a horizontal pole projecting from the mill on the opposite side from the sails. The end of this pole was supported by a wheel and rotation eventually resulted in a shallow ditch surrounding the mill mound. Post mills were in use from the 12th century onwards. No medieval examples of the wooden superstructures survive today but the mounds, typically between 15m and 25m in diameter, survive as field monuments. In general, only those mounds which are components of larger sites or which are likely to preserve organic remains will be considered worthy of protection through scheduling. However, some mills reused earlier mounds, such as castle mottes and barrows, which are worthy of protection in their own right.

The two post mill mounds 560m and 660m north west of St John the Baptist's Church survive in good condition. They will preserve evidence on the structure of post mills, while deposits preserved in the ditches may shed light on a range of aspects of the medieval environment, such as climate, flora and fauna. Their relationship with associated features such as the ancient trackway to the village and ridge and furrow may contribute to an understanding of the economy of the settlement.


Legacy Record - This information may be included in the List Entry Details.


The monument includes two post mill mounds in two areas of protection, situated 560m and 660m north west of St John the Baptist's Church, in a field and spinney that were formerly part of Middle Glebe Field. While the wooden superstructures of the post mills no longer survive, the mounds, which supported their foundations, are preserved as substantial earthworks surrounded by ditches from which earth was dug in the construction of the mounds. The mill mounds, which are situated on the northern side of the ancient Keyston to Titchmarsh trackway, overlie ridge and furrow cultivation remains and are of medieval or post-medieval origin.

The northernmost mound has a diameter of 22m and stands to a height of 2m from the bottom of the ditch. On the south western side it extends into a ramp approximately 3m long, which connected the post mill on the mound with the adjacent trackway. The centre of the mound is marked by a partly infilled depression, now up to 0.5m deep, which is thought to indicate the position of the mill's central post. The encircling ditch is C-shaped and survives as a shallow depression of 1.5m wide, except on both sides of the ramp, where it widens into two small ponds, which are water-filled in winter.

The southernmost mound covers an area 20m in diameter with a height of 1.5m from the bottom of the ditch. The central depression in the top of the mound is less pronounced than that of its northern neighbour and is approximately 0.3m deep. The encircling ditch survives as a shallow depression up to 3m wide, except on the south west where mound and ditch have been cut by a modern boundary ditch, destroying any evidence of a ramp.

All fence posts are excluded from the scheduling, although the ground beneath them is included.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 5 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.


The contents of this record have been generated from a legacy data system.

Legacy System number: 33356

Legacy System: RSM

End of official listing