The Bebelplatz is known as the site of one of the infamous Nazi book burning ceremonies held in the evening of 10 May 1933 in many German university cities. Today a memorial consisting of a glass plate set into the cobbles, giving a view of empty bookcases (large enough to hold the total of the 20,000 burnt books), commemorates the book burning. Furthermore, a line of Heinrich Heine from his play, Almansor (1821), is engraved on a plaque inset in the square: “Das war ein Vorspiel nur, dort wo man Bücher verbrennt, verbrennt man am Ende auch Menschen.” (in English: “That was only a prelude; where they burn books, they will in the end also burn people”).