I wish I could have dragged Cornwall to Berlin to show me his Berlin. The new Berlin - with its magnificent new glass railway station and its vibrantly rebuilt eastern half - is the most remarkable place in Europe, more accessible than London, more intelligent than Paris, more alive than Amsterdam. But what makes the city so remarkable is not its future but its history. The place aches the past - and all its new building, its relentless covering up of history, is actually a futile attempt to escape the inescapable.

The more Berlin changes, the more historical it becomes. Everywhere in Berlin, people point at ghosts, at things that no longer exist. There is the "station of tears", one friend said to me, pointing at the Friedrichstrasse S-Bahn station, the railway terminus which was once the last border crossing point between east and west. And there, somebody else told me, pointing at the street in the front of the Brandenburg Gate, that's where the Wall used to be. If you look closely, he said, you can still see some of the old bricks in the pavement.

I did look closely, but instead of the Wall, I saw Richard Burton as Le Carre's Alec Leamus in Martin Rit's 1965 movie adaption of The Spy Who Came In From The Cold, I saw him waiting and waiting in vain at the old Checkpoint Charlie for the spy who never came in from the cold. And then I looked again and I remembered the end of Le Carre's book, when good old George Smiley, the English Don who always seemed so perfectly at home in the old Berlin, waits and waits in vain for Leamus and the girl to climb back over the wall and come in from the cold.