The park is not a small one, as it stretches across 30 hectares, so one has the room to explore the meanders of the alleys and enjoy the sun for a long time. Besides, there is something more to see at the Parc de la Ciutadella than the alleys – a visit to the Barcelona Zoo is highly recommended, especially for the youngsters, who can both have fun and learn a lot about animals and their habitats. Others, who are more into politics or science, might want to pay a visit to the Zoological Museum or the Catalan Parliament.

Parc de la Ciutadella is located at the site, which formerly was home to the military fortress of Felipe V, who insisted on holding a firm grip over Barcelona once he took control of it after a thirteen months long siege. As a result, in 1714, the King decided to erect a fortress, greater in size than any other in Europe, and so the citadel, whose shape resembles a star, was born. To add to the hatred of the locals towards the seat of the tyrant, a whole Ribera district, was razed to the ground to clear space for the fortress. However, it was reconstructed at another place under the name of Barcelonetta 30 years later. A century and a half after the construction of the Ciutadella, Catalonian general Prim handed it over to the city. The demolition of this hated symbol followed and only three buildings were left standing: the Governor's palace, the chapel, and the arsenal, in which now the Catalan Parliament resides.

In the meantime, in 1872, steps to turn the location into a public park were undertaken but the realisation process was rather slow. In 1885, the park was chosen as the site of the 1888 Universal Exhibition, which boosted its development and resulted in many new buildings springing up on its premises. One of the most notable of them is the Castel dels Tres Dragons (Castle of the three dragons), which was built to resemble a Medieval castle and housed a restaurant during the 1888 World Fair. Today, it's home to the Zoological Museum, or Museo de Zoologia. After the exhibition, at the end of the 19th Century the animal collection of the Zoological garden was moved into the Parc de la Ciutadella. Barcelona Zoological Park first opened its gates on the Day of the Merce, the patron saint of Barcelona, in 1892, covering some 13 hectares of the park’s area.

Except for the Zoo and the Zoological Museum, Parc de la Ciutadella features other interesting sights, such as the magnificent lake at the very centre of the park where you can rent a rowing boat. There's also the Geological Museum awaiting its visitors. Another popular and very impressive sight is the Cascada, a triumphal arch in Baroque style (slightly following the design of the Trevi Fountain in Rome) with a waterfall and a fountain built especially for the 1888 Universal exhibition. The structure, located in the northern corner of the park was designed by Josep Fontsere, the architect who was responsible for the conversion of the former citadel into a park, and the assisting future prominent architect – Antoni Gaudi, who at this time was still a student. Other sculptures adorning the park’s premises, include a large stone mammoth and a metallic cat, as well as a statue of general Prim.