Cinquantenaire Park, Brussels
The Parc du Cinquantenaire ('Park of the Fiftieth Anniversary') or Jubelpark (Dutch for 'Jubilee Park'), is a large public park of 30 ha (74 acres) in Brussels, Belgium.
Most buildings of the U-shaped complex that dominate the park were commissioned by the Belgian Government under the patronage of King Leopold II for the 1880 National Exhibition commemorating the 50th anniversary of the Belgian Revolution. During successive exhibitions, more structures were added to the site. The massive memorial arch was erected in 1905, replacing a previous temporary version of the arcade by Gédéon Bordiau.
The Royal Museum of the Armed Forces and Military History has been the sole tenant of the northern half of the complex since 1880. The southern half has been occupied by the Art & History Museum since 1889, and the Autoworld car museum since 1986.
The original pavilions of the 1880 exhibition, designed by Bordiau, were largely replaced with the arcade designed by Girault in 1904 and the large halls on both sides. Only the glass-constructed Bordiau halls remain from the 1880 structures.
The above information is condensed from the Wikipedia entry.
See also 1880 Brussels National Exhibition