Bourn Windmill is one of the oldest windmills in England and is designated as an Ancient Monument.

Bourn Mill is an open trestle post mill; the entire weight of the body is supported on a central post, which is then supported by a trestle. The sails of the mill have to face squarely into the wind and to achieve this the entire mill is rotated around the central post – a surprisingly easy, but dramatic, task for two or three people.

On open days you can have a go at this task yourself! Check out our What's On/Events page for information.

Bourn Mill provided inspiration for the work of one of our most eminent architects. Lord Foster prepared drawings of the mill whilst studying architecture at Manchester University (see drawings below). He also helped promote our appeal to raise funds in 2003.

There are only around 50 trestle post mills left surviving in the UK, 5 of which are in Cambridgeshire.


Bourn Windmill dates from 1636 – at least that is the earliest record which we have. This style of mill has barely changed from the 13th century, so it may be much older. The machinery dates from the 19th century and the trestle itself was renewed using oak in 1874.

Changing landscape

Over the centuries, the mill has looked out over a changing landscape. The first grain to be brought here would have been grown in medieval open fields, and arrived by packhorse and cart along the track through ‘Mill Field’. In 1806 the open fields were enclosed, and a new landscape of small hedged fields was created.

Changes continue today, with the new community of Cambourne taking its place within the historic landscape of Bourn Mill and linked to the mill by footpath.

Changing hands

The mill changed hands many times over the last four centuries. The first recorded owner was John Cook, who sold the mill in 1636 to Thomas Cook of Longstowe.

By 1701 the mill was owned by John Bishop, a baker, grinding grain for his own bakery. The family owned several mills in the area. In 1741 his grandson, Richard Bishop, was killed when one of the mills blew down as he struggled to turn the sails out of high winds.

In violent storms the miller has to carefully judge the position of the sails to prevent them pulling on the wooden gears and brakes, which might lead to fire through friction. Fire is a big risk in wooden mills. Despite this accident our mill stayed linked to the Bishop family until 1875, and you can see the initials of some Bishop family members carved into the side timber of the interior of the mill.

The last miller

The last miller at Bourn was George Papworth, whose father was the landlord at ‘The Fox’ in Bourn. In 1926 the introduction of a paraffin engine in the barn made the mill redundant, and it was sold for £45.

Mansfield Forbes (1889-1936, pictured below copyright Ian Forbes) was one of the founders of the English department at Cambridge University and a fellow of Clare college. He had many enthusiasms, including windmills. He arranged for the controversial sculpture "Genesis", by the artist Jacob Epstein, to be displayed in Cambridge and he used the income that he raised to purchase Bourn Windmill for us, with additional funding coming from The Pilgrim Trust. It is possible that without his intervention the mill would simply have rotted away until it was beyond repair.

Mansfield Forbes copyright Ian Forbes

Repairing the mill

Traditionally millers spent the absolute minimum necessary to continue the operation of their mill, often resorting to straps and plates which were more in the nature of bandages than cures for ailments. As a result inside the mill much of the fascinating historic fabric is there for us to see today.

Restoring Bourn Windmill

When we purchased Bourn Windmill in 1932 it was in a derelict condition and the charity carried out work to restore it - the photos below are from 1941 and 1966.

Repairs to the mill are undertaken as necessary. The stocks and sails were last replaced in 2003 with grant aid from a number of funders. Repairs were carried out to the trestle timbers and the exterior repainted in 2008/09. In 2016 we carried out repairs to the wooden pads which sit on the brick plinths and in 2017 the sails were re-painted.

The illustration below is taken from Windmills & Watermills by John Reynolds (1970).