The Upper, Middle and Lower Palace Gardens form part of the 8km of green space in the centre of the city – the parks connect with one another so you can walk from the Höhenpark (with a vintage model railway, at Killesberg Messe) via Rosensteinpark & Wilhelma (the typical English garden and Moorish zoo) through the Schloßgarten and finally into Schloßplatz. With a massive beer garden, bridges, the planetarium, lakes and miles of walkways, this is the recreational heart (and lungs) of the city. City planners kept about half of Stuttgart’s area green to ensure clean air but with the continuing rise in industry, even this ratio might not be enough.