"In 1964 I returned to Salem and informed the Board of Governors that in addition to the work agreed to in my contract, I intended to build up a documentation of all Hahn’s activities; this has now become the
Kurt Hahn archives. And that I intended to try and found an association of the schools started by Hahn himself, his colleagues or his pupils. 

While we [i.e. Round Square] are only concerned with the association, the archives are complementary and you could hardly have the one without the other; if Hahn’s ideas were to survive, then it could not only be by legend and hearsay, but by collecting all the documents relative to himself, and his work. The Governing Body agreed to my proposals and I would like to record my gratitude both to the Board and the Direction of Salem for allowing me to travel and build up the conference in addition to my responsibilities in the school." (JWY, taken from his Round Square valedictory speech "Muscles of friendship", 1992 ∆)

For 25 years JWY collected everything relevant to Kurt Hahn, Salem, Gordonstoun, Outward Bound, Duke of Edinburgh’s Award, the United World Colleges, and Round Square. Initially, he collected everything in a drawer, then in a cupboard. Later a little store room and eventually a large room in his own apartment in Salem became the Kurt Hahn Archive. Furniture was provided by Salem school and some Salem Alumni. Salem provided him with an assistant,
Petra Blechschmidt, to help him catalogue it all. When his daughter, Sophie, took over in 1990, there was already an enormous collection of writings. When Sophie retired from the position in 2010 there were approximately 140 metres of papers. It had become the central archive on Kurt Hahn.

"But how, as Max Weber asked, do you convert charisma into structure? How can there be a Kurt Hahn school without the man himself? A school, moreover, that neither mindlessly regurgitates nor carelessly forgets the founder's principles. 

To a considerable extent my father's work consisted in trying to come up with viable answers, two of which were especially important to him. The first was to provide the structure with a memory. This was the
Kurt Hahn archive. It was neither his personal hobby nor a collection of old relicts, and it was certainly never intended to be a temple, but a space of engagement and historical self-orientation. The second, more important response was (to use a word he would never have employed): wiring. This was Round Square. [...]" (Geoffrey Winthrop-Young, in his memorial address for JWY, Salem, May 1st 2012 ∞)

References:

*  Family collection

º  Kurt Hahn Archive

∆ Round Square

∞ Salem