MP4 was one of 11 planned towers on Guernsey, and the most unique of the 5 completed (except for perhaps MP5 at Vale Mill). It is located at Pleinmont, near Batterie Generaloberst Dollmann. The roof would have mounted a Freya radar in an open position, and could be accessed by a ladder from the top floor.
Access today is possible, as the tower lies derelict. However, extreme care must be taken as the tower is in a advanced state of decay, and areas such as the stairs may be very hazardous as there are no handrails, the staircase is narrow, and covered with debris.