Some other popular sights are the Waterloo Column, the Laves House, the Wangenheim Palace, the Lower Saxony State Archives, the Hanover Playhouse, the Kröpcke Clock, the Anzeiger Tower Block, the Administration Building of the NORD/LB, the Cupola Hall of the Congress Centre, the Lower Saxony Stock, the Ministry of Finance, the Garten Church, the Luther Church, the Gehry Tower (designed by the American architect Frank O. Gehry), the specially designed Bus Stops, the Opera House, the Central Station, the Maschsee lake and the city forest Eilenriede, which is one of the largest of its kind in Europe. With around 40 parks, forests and gardens, a couple of lakes, two rivers and one canal, Hanover offers a large variety of leisure activities.
How many parks are there approximately in Hanover?
40