Of Barcelona's parks, Montjuïc is the largest, with 203 ha located on the mountain of the same name. It is followed by Parc de la Ciutadella (which occupies the site of the old military citadel and which houses the Parliament building, the Barcelona Zoo, and several museums); including the zoo), the Guinardó Park (), Park Güell (designed by Antoni Gaudí; ), Oreneta Castle Park (also ), Diagonal Mar Park (, inaugurated in 2002), Nou Barris Central Park (), Can Dragó Sports Park and Poblenou Park (both ), the Labyrinth Park (), named after the garden maze it contains. There are also several smaller parks, for example, the Parc de Les Aigües (). A part of the Collserola Park is also within the city limits. PortAventura World, one of the largest resort in Europe, with 5,837,509 visitors per year, is located one hour's drive from Barcelona. Also, within the city lies Tibidabo Amusement Park, a smaller amusement park in Plaza del Tibidabo, with the Muntanya Russa amusement ride.