Stumbled on this information, anymore knowledge, maps, etc.
The following reference in Hansard:
PRISONERS OF WAR.
HC Deb 10 July 1918 vol 108 cc295-6
"36. Captain BARNETT asked the Under-Secretary of State for War whether he is aware that the Railway-men's Convalescent Home, Leasowe 296 Castle, Wallasey, which was commandeered early in the War for use by British troops, is now occupied by German prisoners of war; whether these prisoners or some of them are employed in repairing the sea wall; whether their employment in close proximity to the Irish Sea is either necessary or desirable; and whether, in view of the strain which has been thrown upon railwaymen by the War, he will take steps to secure that this convalescent home shall be restored at the earliest possible moment to its proper use? "
Also & I did not know about this one which is quite interesting:Bidston Hill
HC Deb 12 November 1918 vol 110 cc2544-5W.
"Mr. L. SCOTT asked the Under-Secretary of State for War whether he is aware that until recently there was a very well-built and equipped camp accommodating about 1,400 men, all the huts being on concrete blocks, on the west side of Bidston Hill
, near Birkenhead; that this camp was recently dismantled and taken up, including the concrete foundations, and the equipment removed; that the military authorities have now again requisitioned the site for use as a camp for German prisoners of war and are now engaged in rebuilding it; and whether he 2545W will give full particulars of the causes of this waste of public money and see that those responsible are held to blame?
Owing to the difficulty in obtaining supplies of new hutting, it became necessary in August last to transfer some of the sectional hutting at Bidston to provide accommodation for American troops. Recently, at the urgent request of the National Union of Railwaymen, it was decided to give up the occupation of the Convalescent Home at Leasowe Castle belonging to the union. To enable this to be done, it is necessary to transfer a number of German prisoners of war, and as there was no other accommodation available for them, it was considered that the most economical arrangement was to use what was left of Bidston Camp and provide additional accommodation required by the erection of some hutting which was available."
So it look like they were moved out of Leasowe Castle to Bidston Hill
"German prisoners of war were housed in Leasowe Castle. It's low lying around here, the River Birket filters off much of the surface water. By 1917 the watercourse was in disrepair, and the engineer in charge of the Birkett renovation scheme applied to the Cheshire Agricultural Committee for a workforce of German labour. In early September 140 prisoners arrived as labour to clear the Birkett. The prisoners and their armed escorts were housed at Leasowe Castle for almost the duration of the war. By mid August they had cleared of weeds, reeds and silt a distance of 1200 yards. An additional request for a further fifty men with guards was granted. Later objections concerning the good accommodation of the POW's compared to the battalion on Bidston Hill
(outside Birkenhead) resulted in a change of billets. The prisoners were paid for their agricultural labours and appear to have done quite well out of the arrangement."