Hello all!
Happy new year everybody!
The three diamonds are actually three squares with the "H" symbol in a dotted triangle...so it seems like US Army training grounds on a former airfield...as for the airfield itself it looks like one of these many old navy training bases around Chesapeake Bay (and elsewhere on the West Coast); I have thought for a while it may have been a former German Fliegerhorst but the disposition, hangar location, size of runways and tarmac are all wrong...I would say US, really...
