GeoGraph - photograph every grid square

MP1 Naval direction and range finding position.
The massive 16 metre high tower was built between April and October 1943 requiring an estimated 5,000 bags of cement.
A 2cm anti aircraft gun was fitted on the roof.
One of only three that were built out of 9 planned around Jersey.
It was thought that any two towers seeing a target could report their bearings from which the range could be determined, but was found difficult to use with multiple moving targets.
The 6 metre stereoscopic range finder (seen located behind the tower) worked on its own without communication delay problems.