The towers in the docks. They were originally built in 1913
and adapted for WWII. The eastern one was changed to an observation post
with a 4.7" gun placed on top. The western one was an extended defence
officer post for minefield control also with a 4.7" gun on top. The central
one unfortunatly i have no information for. In front of these was a small
observation post which still has the original shutter in place.

Thanks to Kyn for the picture.