Best visited at night, as it is more evocative then, Bebelplatz is a square along Unter den Linden. Located here is an eloquent memorial to the notorious Nazi book burning that took place on the night of May 10, 1933. Through a window set in the pavement, you can look below to a small library lined with empty bookshelves. Some 25,000 books were burned, all by authors considered enemies of the Third Reich. Nearby is a plaque with the prophetic words of the poet Heinrich Heine. In 1820 he wrote, 'Where books are burned, in the end people will burn.'