Our visit to the Haringvliet Expo was a disappointment.
We were there on a rainy Sunday afternoon in June, expecting an interesting museum and guided tour of the Haringvliet dam.
This dam is part of the Delta Works that protect the Netherlands from the sea in case of storm.
Unfortunately, the guided tour required at least 4 people to start, and it was just the two of us.
Instead, we were allowed to enter for the price of one (6.50 euros) and watch two 15-minute movies about the flooding disaster in 1953 and the building of the Delta Works. These movies were at least 30 years old and made by the public works department, so it's strange to be charged such a relatively large amount of money to see them. However, the movie about the disaster of 1953 was quite moving.
That was it, and the "Expo" did not have anything else to offer.
Besides, the old man who helped us was far from friendly or willing to explain anything.
You're far better off visiting the Keringhuis at the Maeslantkering near Hoek van Holland. They give a proper tour and have an interactive museum.