Marsh Lock
The 928th tallest dam in the world
Marsh Lock is a lock and weir situated on the River Thames in the civil parish of Remenham, which is in the English county of Berkshire. The lock is about 1 mile (1.6 km) upstream of Henley Bridge and the centre of the Oxfordshire town of Henley-on-Thames. It is close to the Berkshire bank, but accessed from the Oxfordshire side via two long walkways, the downstream one being near Mill Meadows. The first pound lock was built by the Thames Navigation Commission in 1773. The weir consists of a series of iron watergates running from the lock to the Oxfordshire bank near the mills. It is situated between the two walkways.
Dam data from Wikidata (CC0) plus curated additions. Summary from Wikipedia (CC BY-SA).