Watch Marina Jenkins' report with Jersey War Tours guide Philip Marett
A non-profit group in Jersey which has special access to some Second World War fortifications have acquired the keys to another.
Jersey War Tours is run by volunteers who are passionate about informing visitors about the German Occupation and impact it had on the island.
Philip Marett, one of the tour guides, took ITV News reporter Marina Jenkins around two of Jersey's least-explored fortifications.
The Napoleonic tower at Greve de Lecq was modified by German soldiers at the start of the war.
Philip said: "It looks like for four years it was a bit of a holiday camp for the folks stationed here.
"They've arrived here [Jersey] and won the lottery about where they could have been posted. It could have been the Russian front or the Norman front but they've ended up here."
But on 6 June 1944, the Battle of Normandy began and the tower sprung into action.
The soldiers would have seen hundreds of allied planes fly past, from England to the north coast of France.
Philip said: "The anti-craft gunner on the roof is going to see this but there's not enough power to actually hit them as they're too far away.
"The American troops will cut the peninsula in half and by 13 July  any view from the tower is now American-occupied France and not German-occupied France.
"The Germans are now facing the enemy and an invasion is likely at any point."
There are more than 500 fortifications in Jersey including bunkers, towers and fortresses.
Many sit in plain sight and are passed every day by islanders. But there are some which lie in much more secluded spots.
The Germans decided to build their battle headquarters in Jersey on the border of St Lawrence and St Peter parishes.
It was strategically built here as the furthest point of any potential invasion on their army.
Jersey War Tours, along with the Channel Islanders Occupation Society (CIOS) have recently got the keys to the site.
The bomb proof fortress spans two floors and contains offices, communication rooms and living quarters.
The thick concrete walls are even lined with wooden paneling.
Philip said: "It was very well hidden and originally disguised to look like a house. It has chimney pots on the side and it would've had fake French windows.
"The wooden paneling makes it a bit more homely for them. They can pin things up and draw things on it. But it also acts to absorb shrapnel if there's an explosion."
CIOS and Jersey War Tours are working together to restore the bunker. Once complete, Philip and his team are looking forward to including the site in their tours.
Philip added: "We can take more visitors to sites that they wouldn't normally get to see. Hopefully the funds coming into places like this through the tours will help add more value to preserving it and restoring it for the future.
By preserving fortifications, Greve de Lecq's tower and the battle headquarters, the hope is that more islanders and visitors can learn about the history of the German Occupation.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know...