This small museum celebrates the world's first underwater tunnel, built here in 1843. The tunnel was the brainchild of engineer Marc Isambard Brunel (father of Isambard Kingdom Brunel, another famous structural engineer), who had thought of a tunnel as an alternative to a bridge to allay congestion on the Thames. The museum has fascinating exhibits retracing the project's (mis)fortunes and the pioneering technology used to dig the tunnel. Visitors can access the tunnel shaft, the former Grand Entrance.
Works started in 1825 and the tunnel, initially designed for pedestrians (it is now used by trains), opened to great fanfare in 1843. The Grand Entrance now regularly doubles as a concert venue and pop-up bar, much as it did when it first opened. Guided tours (two hours, adult/child £10/free) meet at Bermondsey tube station at 10.40am on Sundays and Mondays, and 6.15pm on Wednesdays. The museum also runs longer boat and walking tours (three hours) from Embankment tube station (10.40am from Tuesday to Saturday).