Formerly the largest military citadel in Barcelona was set on the grounds where we now have the Ciudadela Park. It had been built by Philip V after the War of the Spanish Succession in the 18th century. By the end of the 19th century the area was gained by the citizens, and only a few buildings remained, like the Catalan Parliament, once the armory.
The Ciutadela is a huge green space in the middle of the city. There is a beautiful lake in the centre of the park where you can rent rowing boats. Other highlights are the sculptures and monuments constructed for the World Exhibition in 1888, chaired by the renowned modernist architect Domenech i Muntaner; the zoology museum is one of his works, and functioned as a restaurant during the Exhibition, or the cascade by Fontsere. The Zoo, one of the oldest ones in Europe, is a must-visit for all children. Other spots worth visiting are the nice Greenhouse and the "Umbraculum" (shaded place for plants).
Another reason to visit the Ciutadela is the general atmosphere that reigns here. It is an ideal place to relax, read the newspaper or have a coffee, and there are always people practicing tai-chi, capoeira, jogging, juggling, playing the guitar or playing ping-pong on one of the especially designed tables. During the season, many festivals and fairs for a broad public are held there.