Support Defence Post L22 is a unique Defence Post, probably of the Category A design, i.e. pre-1939. It has the familiar tower, but unlike the later towers this is intended to be used for small arms fire on the second floor and observations on the third level. The rear of two storeys is rectangular. It is possible that this was a prototype of the Category B and C Defence Posts building after 1939 as it has very similar attributes.
The defence post has now been engulfed in new housing flats.