I often wondered about this building when attending FOSDEM.

This 'courthouse' is not just any courthouse, it's the biggest courthouse in the world, it is so big that it was the biggest building in the world until NASA made the VAB to build Saturn V. Bigger than St-Peter's Cathedral, it is a demented place erected at the top of Belgium then industrial might, costing then more than half the entire state budget for public construction during the 20 years it took build. The architect was given unlimited budget and complete freedom. It was supposed to be even bigger with a ziggurat styled tower to top it off but the architect died before the completion of the building. A more reasonable golden dome was constructed instead. Still to this day nobody understands how this was allowed to be made, and it is way too expensive to maintain, and has thus fell in disrepair, but it is also too big and too incredible to demolish

There are renovation works ongoing, I jumped a fence and took a sneak peak, and I think it's going to be great.

Here is a website with some pictures: - https://tchorski.fr/12/palais-01.htm - https://tchorski.fr/12/palais-10.htm