Currently Burton Mill is in the throws of an ambitious restoration project and is only open to visitors for the National Mills Weekend (see the official site for details). It was acquired by its current owners in February 2016.
Thus far they have restored the Gilkes Turbine and have had it successfully generating electricity. They hope to be able to start milling corn in time for the next open day in 2018.
The most striking thing about the site is the enormous mill pond. Back in Elizabethan times this area was the site of a huge iron-making industry, and the pond was originally a hammer pond driving the foundry bellows and huge mechanical hammers which could pound iron with up to 150 blows a minute.
In the 1780s, once Abraham Derby of Coalbrookdale perfected the smelting of iron using coke rather than charcoal, this trade moved to the coal producing areas, and in 1790 the mill was rebuilt in its current form as a corn mill but with two waterwheels, one on either side of the building.
In the late 1890s cheap imported wheat meant that most milling moved to huge roller mills at the ports. Burton turned to electricity generation to supplement its income. The eastern waterwheel was replaced by an early Francis Turbine the remains of which are displayed at the front of the mill. The western one was replaced in 1929 by the recently restored Gilkes Turbine. At that time it was used to power a saw mill.
The whole mill became disused in around 1970, but was restored using a pair of stones taken from a mill in Wales coupled to the western turbine. It carried on producing flour until the late 1990s.
My thanks to the good folks at the Coultershaw Heritage Site and Beam Pump for pointing out that Burton Mill was open on the day I visited.