It's a very dark, damp and cold place to visit.
I've been going here a a little kid, as Vicki was intrusted in the german occupation of the channel islands.
My last visit before i went in September was about 5/6 years ago, the museum since than has changed quite a lot.
It is more on how the German army was seen to the Islanders. Before it was more about how the Hostipal was built etc.
The unfishned tunnels are just how they were left.
At one point i think you are 35 feet /meters (sorry can't rember which), underground.
All over the island of Jersey there are plaques that are dedicated to the memory of Islanders who tried to leave the island by sea, while under occupation.
With the tunnels there a rowing boat thats some of the islanders escaped from using , this can be found in the shop.
Near by there still are the trenchers that the germans dug out, these can be found on a short walk.