The finest of Leopold II’s grand projects, the Parc and Palais du Cinquantenaire were built for the Golden Jubilee celebration of Belgian independence in 1880. The park was laid out on unused town marshes. The palace, at its entrance, was to comprise a triumphal arch and two large exhibition areas, but by the time of the 1880 Art and Industry Expo, only the two side exhibition areas had been completed. Further funds were eventually found, and work continued for 50 years.

Before being converted into museums, the large halls on either side of the central archway were used to hold trade fairs, the last of which was in 1935. They have also been used for horse races and to store homing pigeons. During World War II, the grounds of the park were used to grow vegetables to feed the Brussels people.

Housed in the south wing of the Cinquantenaire Palace, Autoworld is one of the best collections of automobiles in the world. There are some 300 cars, including an 1886 motor, and a 1924 Model-T Ford that still runs.