This photograph shows the pens where the German Imperial Marine stored its submarines during the First World War. The destruction of these installations was undertaken by the retreating German forces commencing in September 1918.

This document was brought to the attention of the U-Boat Project 1914-18 by William Davies's grandsons, John and David Davies, Denbigh, who inherited their grandfathers' documents and naval artefacts and kindly allowed us to share it.