This is not in Belgium, but in Béthune, France, although not far from the Belgian border.
The belfry (the tower) is originally from 1346, but was destroyed during the first world war and rebuilt between 1921 and 1923. You can find it on Google Streetview from almost the same point as your photographs have been taken.
Image source: Wikimedia Commons
How did ...
The church would appear to be the Grossmünster in Zürich.
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The towers are quite distinctive, and the tip of the spire at the rear of the church (seen here between the towers) is just visible in your photo to the left of the left tower.
The building in the foreground of your photo - the Haus zum Rüden* - appears to the left in this image, and ...
I would suggest asking the Nuremberg Municipal Museums about this image or others tagged as Nürnberg.
Local museums are often interested in receiving such images taken by visitors since sometimes angles, viewpoints or a timeframe may complement their existing collections.
Based on @Arthur'sPass answer, which looks to me like a realistic candidate, the ...