A l'abandon.be - Abandoned sites around Brussels (in French).
Abandoned-Places - Great photographs of abandoned buildings in Belgium, with a focus on the photography.
Abandoned Zone - Flash-only, frill-heavy black and white photo gallery focussing on tunnels and abandonments around Antwerp.
Brussels Underground Exploration - Explorations of quarries, mines, drains, abandoned stations and the like under Brussels (in French and English).
De Onderwereld - Great pictures of a wide variety of abandoned sites and tunnels. English captions.
Exposed Photography - A site dedicated the photography of old, abandoned factories and mines around Antwerp (in English).
Forgotten Places - Well-described photo galleries depicting a wide variety of abandoned sites in Belgium (in Dutch).
Green Explorers - Very nice pictures, unfortunately obscured by a barrage of pop-ups and other crap. Organization could also use work.
Lab-Wan - Photography and night photography of desolate places such as abandoned hospitals and factories.
Urban Exploration Front - Black-and-white photos of abandoned sites around Ghent.
Urbanprojects - A straightforwardly designed page featuring photos and descriptions of various sorts of abandoned sites.
Urb-Ex.com - Photography site with an artistic angle.

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