In Guernsey there are many different bunkers and historical landmarks which you can go and explore. Each one has a different history and would have had a use in the war when the island was occupied by the Germans. At most of these bunkers, there are information boards, telling you a brief history of the bunker. Most bunkers you can get in on your own without needing to pay or go with a tour guide. Whereas some of them are blocked off but can be accessed by paying and going for a tour. Some of the open to the public bunkers, can be slightly muddy or dirty, so if you are going to explore, i would take old clothes. Believe it or not, not many of the bunkers in Guernsey are graphite-ed most are still clean and original. Some of the bigger bunkers and land,arks, such as castle cornet and others, you have to pay to enter, and not everything in there is accessible. But this is only for a select few. some have been made into museums, and some are privately owned by residents. so make sure when you go to explore the bunkers, they are not privately owned or on private land, as some have been made into either storage or games rooms.