These Mosquitos stand in the very place where the first prototypes were built in great secrecy by de Haviland at the beginning of the Second World War. The site is Salisbury Hall, an estate and farm some 18 miles from the centre of London and six or seven from what was the de Havilland factory at Hatfield in Hetfordshire.
The site is now the de Havilland Aircraft Heritage Centre, established in 1959 and run by a dedicated team of volunteers who also do all the restoration themselves.
The first completed Mosquito was dismantled and taken by lory to the Hatfield aerodrome where it was successfully flown for the first time by de Havilland himself, or so I was told by Ralph Steiner who showed a group of us around the centre. Almost more remarkable was that the next few prototypes were flown out of a grassy field near where they were built and again test flown by de Havilland. Just one of the stories about this remarkable aircraft. A lot more can be found on the Internet and it is well worth starting here: