Archaeological monitoring of the excavation of a service trench on land adjacent to Martello Tower P, Felixstowe, was undertaken during March 2013. The tower dates from the early 19th century and is a Scheduled Monument. During this work a surface of pale mortar with small brick fragments and pebbles, c. 8.5 cm thick, was recorded at a depth of 0.6m below the present ground surface. A small area of brickwork, which may have been a wall base, was located crossing the trench at an angle approximately 2m to the west. It was sitting on a similar material situated at the same depth. These features have been interpreted as the remains of a structure. The surface was cut by a concrete anchor for a mast that was erected around 1900. An encircling ditch, as identified during an earlier evaluation, was seen in the area adjacent the tower.