The connection of a mountain north of Belfast to WWII can still be seen today by the presence of a white stone.
A local postman was hired by the Ministry of Defense in 1941 to paint a large rock on the mountain white.
The stone, at Cave Hill, was used to help guide Allied pilots at airfields in Belfast at the time.
In recent times, a plaque on the mountain to mark the war effort has been defaced.
Activists are urging the public to treat the surrounding mountain with respect.
Video journalist: Niall McCracken