This is a Russian gun on a steel carriage, it only differs in detail to the guns used in these forts during WWI now for some reason i didn't read the cards that where by the guns. Not enough time the tour took three hours we started at two and some time after five we where back at the start and it was getting dark. We walked some 4 km (2 1/2 miles). And also those guns come from the klm-mra (our national army museum). They looked very familiar to me I've visited that museum so often (it was free) and not only that, there's a car museum (autoworld) and the museum of ancient art. (Egypte, Greece, Rome, you know a lot of BC, witch was also free).