The Barcelona zoo is inside the Ciutadella Park (literally the citadel park). So you have a 15 minute walk from home so surely you will have to go. The zoo is pretty standard but the kids will enjoy it.
The Parc de la Ciutadella is the largest in the center of Barcelona. It’s not great by northern standards, but here in the south we do not have so many parks.
There are three playgrounds and a lake where you can rent a boat.
The park was built for the Universal Exhibition of 1888 on what was a military citadel, and hence its name. The only remaining building of the citadel is now the catalan regional parliament. The citadel had been built in 1714 after the war between Habsburg and the Bourbon, in which Barcelona was in the losing side (as always). To build the citadel, thousands of houses in the neighborhood were destroyed, and its function was not to defend Barcelona but to punish it.
On the way to the park you can visit a couple of interesting buildings. The first is the Mercat del Born (Plaça Comercial 12), a market built also for the 1888 exhibition. It has been recently renovated and is very beautiful. Now it is no longer a market but a museum where you can visit the remains of the houses that were destroyed in 1714 to build the military citadel. It has a certain pro-independence bias.
The second building is the Estació de França (Marqués de l’Argentera), a very nice train station that was built for the second universal exhibition that was made in Barcelona in 1929. It is still in operation, our children like it a lot.
