 Complete the following phrase:  The Cinquantenaire Arcade ,  was planned for the exhibition of 1880 and was meant to commemorate the 50th anniversary of the Belgian Revolution. In 1880, only the bases of the memorial archs columns were completed, and during the exhibition, the rest of the arch was constructed from wooden panels. In the following years, the completion of the monument was the topic of a continuous battle between King Leopold II and the Belgian government, which did not want to spend the money required to complete it. The park was also the site of the 