Next to the bigger Kriegsmarine Peilstand und Messtellung, MP 1 to MP 3 towers the Germans build 9 smaller observations posts. This observation post is number 4. Post number 4 lies near Sorel at Jersey in the United Kingdom. The Soral strongpoint was spilt in Sorel A and Sorel B. The observation post M4 lies in Sorel B.
There was a open gun emplacement with a 10,5 cm field gun. A Tobruk with an MG for close defense and a personnel bunker. Today observation post is sealed up, even its observation slits are closed as is the personnel bunker and Tobruk. The observation bunker does have two machine gun openings and is situated in front of a small lighthouse.
The M4 Sorel B location can be visited by car, a small car park is in the middle of the Wiederstandsnest.