Eynsham LockOxford
Oxon OX29 4BY
Visitors using the B4044 road from Eynsham to Oxford have to cross the River Thames using the Swinford Toll Bridge.  As you cross the bridge you will see downstream the Eynsham weir and lock.
The lock was built in 1928 as part of the then Thames Conservancy's plan to make the Thames navigable upstream as far as Lechlade-upon-Thames.  It was one of the last to be cut to negotiate a weir which had been there since medieval times.
Six hundred years or so ago Eynsham Weir was owned by the Benedictine Abbey who used it to trap fish for the abbey.  The river has carved a horseshoe-bend at this point so a flash weir was built.
First a Flash Weir then a Pound Lock
A Flash Weir was a movable dam; it could be swung open to let boats down, but they had to be winched over it on the way back up. This system wasted water, and often caused flooding of riverside meadows.
In 1928 a Pound Lock was cut across the neck of the horse-shoe-bend and this is how we see the lock today.  The lock keeper not only operates the lock gates but he is also responsible for regulating the water over the weir managing any flooding downstream.  He checks the level of the river at the weir three times a day.
It  is a delightful spot to spend some time, watching all sorts of craft working through the lock, or studying the varied birdlife such as kingfishers, herons, crested grebes, and common terns.  You might even see some otters in the river.
Facilities include toilets and picnic tables.  There is virtually no car-parking nearby unless you're a customer at the Talbot Inn (not a bad idea) who have ample parking.
Getting There
The lock is about half a mile (0.8kms) from Eynsham. The Eynsham Community website has detailed instructions on access at Web:Eynsham Lock
Google Map - Eynsham Lock