For more than 300 years defences have stood on Mont Crevelt at what is now the southern side of the entrance to St Sampson's Harbour.
The earliest documentary evidence for any defences on the hill is a watchtower in the 1680 Legge Report, a review of the island's defences. The report says it was armed with two iron sakers, a type of cannon named after the saker falcon, a large hawk native to the middle east.
Crevelt means split or open mount maybe referring to the hill's position overlooking the Braye du Valle, the channel of water which used to separate the Clos du Valle from the rest of Guernsey.
During the German Occupation in the Second World War the area was fortified as a resistance nest known as Widerstandsnest Krevelberg, with armaments including one 10.5cm gun, two 4.7cm anti-tank guns, one heavy machine gun, three flame throwers and two 2cm anti-aircraft guns