Fort Werk aan de Hoofddijk in Utrecht

You're standing at Fort Hoofddijk, on the eastern edge of Utrecht. It was built between 1877 and 1879 as part of the New Dutch Waterline. Why then? Guns and explosives had improved so much that the old forts close to the city were no longer good enough. So a new ring of forts was built, around three and a half to four kilometres beyond what was then the edge of town.