The Grönsund Coastal Stronghold

The Grönsund stronghold

The Grönsund stronghold was built according to the political 1909 defense agreement as part of a larger overall plan for the defense of Sealand.
The stonghold was constructed over the years 1912 – 1915.

The Grönsund stronghold should protect the southern waters of Zealand.

It consisted of the Masnedö  Fort ,the Borgsted Battery and the Haarbölle Battery.