The neoclassical facade of Aegidium (named after the patron saint of the municipality where the building is located) barely hints at the extraordinary architectural ensemble hidden behind it. Built in 1905 to a design by architect Guillaume Segers, the complex of banquet halls opened in December 1906 and quickly became the center of the city's nightlife. The Moorish Hall, originally a banquet hall, was converted into a cinema in 1913 and was known from then on as the Diamant Palace. After the death of the original owner, the building was acquired and transformed into a dance hall. Naturally, this also meant a new name: Panthéon Palace.

In 1929, the complex came into the possession of a canon. He commissioned architect Léon Denis to carry out a number of renovations and renamed the complex Aegidium. From then on, it would become a meeting center for the local population, with all kinds of social and cultural activities.

The interior is remarkable to say the least, and incorporates various architectural styles. From the Art Nouveau cloakroom, a monumental grand staircase in pink marble leads to a Beaux-Arts landing. The staircase and landing are illuminated by a spectacular skylight. From the landing, on the left, there is an access to the polygonal conference hall in Neo-Rococo style, mixed with Louis XV style, and on the right to the large banquet hall in Moorish style. An unfortunate renovation in 1956 by architects Jean Hendrickx and Yves Stevens resulted in a stylistic break in the conference hall with the addition of a concrete ceiling, vertically dividing the hall into two parts.