"The church, on Koekelberg hill, is a landmark on the Brussels
skyline. It is the largest building in Art Deco style in the world, at 89 m (292 ft) high and 164.5 m (540 ft) long (outside length). The cupola platform affords an excellent city panoramic view of Brussels
and the wider area of Flemish-Brabant. The central nave is 141 m (463 ft) long, and at its widest the building is 107 m (351 ft). The cupola has a diameter of 33 m (108 ft). The church accommodates 3500 people.
The building combines reinforced concrete with terracotta layering, bricks, and dimension stone. Belgian painter Anto Carte (1886–1954) designed the eight stained glass windows representing the life of Jesus.
This enormous building houses Catholic Church celebrations in both main Belgian national languages (Dutch and French), as well as conferences, exhibitions (as in 2007–2008, the International Leonardo da Vinci Expo), a restaurant, a Catholic radio station, a theatre and two museums." (Text from Wikipedia).