The Great Mosque of Brussels is located in the Cinquantenaire Park. The original building was built by architect Ernest Van Humbeeck in an Arabic style, to form the Oriental Pavilion of the National Exhibition in Brussels in 1880. At that time the pavilion housed a monumental painting on canvas: “Panorama of Cairo”, by the Belgian painter Emile Wauters, which enjoyed major success. However, lack of maintenance in the twentieth century caused the building to gradually deteriorate.
In 1967, King Baudouin lent the building to King Faisal ibn Abd al-Aziz of Saudi Arabia with a 99-year rent-free lease, on an official visit to Belgium as part of negotiations to secure oil contracts. The building was turned into a place of worship for the use of Muslim immigrants to Belgium, who at the time were notably from Morocco and Turkey.
Wikipedia https://en.wikipedia.org/wiki/Great_Mosque_of_Brussels
Coordinates 50°50'36.386" N 4°23'16.07" E