The River Hull Tidal Surge Barrier was built in 1980 at the point where the river meets the Humber. It is a guillotine-style gate — yellow-painted and unmissable — that is dropped during tidal surges to prevent the river backing up into the city. It is operated by the Environment Agency and has been deployed several times during major storm events, including the 2013 surge that flooded large parts of the Humber estuary.
You cannot enter the barrier itself, but it is a striking object close up: best seen from the riverside path beside The Deep, or from the western quayside near the Marina. Information panels nearby explain how the barrier works and how often it is closed.