Along the South edge of the plateau, close to the cliff overlooking Rosia Bay, is a concrete lined trench from WWII. This trench is ‘U’ shaped, with a concrete structure on the tip of the southern corner. This does not look like the usual crew shelters and may have been for rockets or a similar munitions.
The trench itself has crenelations on the side overlooking Rosia Bay. This was obviously intend as an infantry fighting position.
It is possible that there was some type of mount in the center of the U and this trench was also for the servicing crew.
Exact use to be confirmed.