For two decades, Festung Guernsey has been restoring the island’s wartime fortifications.
Since 2005, volunteers from Festung Guernsey have been clearing, painting and fixing fortifications that were originally built in Guernsey by the occupying German forces between 1940-45.
Their mission is to ensure that these historical landmarks are maintained for future generations.
Their restoration work at Batterie Mirus was shown to Princess Anne during her Liberation 80 visit in May.
The group has been invited to celebrate their 20th anniversary at Government House.
Festung Guernsey’s Steve Powell says it's an honour.
“For 20 years, we have strived to honour the sacrifices made by those who lived through the occupation and to provide educational opportunities for all who wish to learn about this pivotal period in our history.
"It has been hard work, but the end result is worth it.
"I hope that our work inspires the next generation, and we will continue to see an influx of volunteers who recognise the significance of these fortifications.”
Chairman Paul Bourgaize says he's proud of the projects.
"It can be quite a laborious process.
"Sometimes they are flooded, so we have to pump them out, dry them out and then do concrete repairs, before we have even started putting some paint on the walls.
"Months and months and months of work just to maybe get one room back to how it was.
"Keeping the island's wartime history alive, that is what we focus on."

Guernsey man stuck in Sri Lanka by the Iran war
More than 25 puffins a week wash up on Channel Island beaches
Guernsey's Water Lanes to remain uncovered
Guernsey's greenhouse gas emissions fall
Work on Guernsey's Victor Hugo Centre may begin by Easter '27
Channel Islands mobile portability issues to be resolved soon
Channel Islanders in the Middle East told to follow local warnings
Freehold of Guernsey's Premier Inn for sale