The streets of the old Jewish quarter, which once stretched from Waterlooplein to the Nieumarkt, were destroyed during and after the Second World War. Although most of its heritage has disappeared, some vestiges remain: Rembrandt's House, the Museum of Jewish History occupying four synagogues. Waterlooplein, with its lively flea market (Waterloomarkt), has the NAP, the Amsterdam height reference point from which all Dutch altitudes are calculated.