The first lock was built of stone by Daniel Harris for the Thames Navigation Commission in 1791.

It is one of the commission's early locks and like St John's was built by J. Nock.

Previously the keeper lived at Eynsham and covered the whole stretch from Newbridge to King's Weir.

The lock can be reached (by authorised vehicles or on foot) from Farmoor on a track behind the reservoir.

The river winds past Farmoor Reservoir and Bablock Hythe where there used to be a ferry.