The Three Mills are former working mills and an island of the same name on the River Lea. It is one of London’s oldest extant industrial centres.
 
It is thought that there were eight or possibly nine mills on the River Lea in Stratford at the time of the Domesday Book (though this number may refer to the number of pairs of millstones rather than buildings). These are the earliest recorded examples of a tidal mill system. In the clock mill there were 16 workers.
 
They created grain for Gin and gunpowder!
 
interesting facts...
The site is home to the House Mill, which is considered one of the world’s largest surviving tidal mills. It functioned by trapping high-tide water behind sluice gates, which was then released to power the waterwheels as the tide receded.