A summer house built by a lake outside Berlin in the 1920s reflects much of Germany's 20th century history. Its first owners fled the Nazis. The Berlin Wall was built through its garden. Then after the reunification of Germany it was recognised as a historic monument and made into an education and reconciliation centre. Alex Stanger has been speaking to Thomas Harding whose great grandfather built the house, and who has written a children's book about its changing place in the world.

Photo: The Alexander Haus today. Credit: André Wagner