"This is the headquarters of the I.A.R.C. and that is my room marked with arrow. This building was built during the war as municipal buildings but we turned them all out of it - French, belgians, Americans and the British all have their offices here".
"The Berlin Hilton welcomes Mr Heath". He must have stayed in that room marked with his circle and cross . . .
The (X) is beside the Police Station, I wonder if he stayed there free of charge?