Fort de la Chartreuse in Liège, Belgium

The Fort de la Chartreuse is a 150-year-old fortification that once defended the Belgian neighborhood of Liège, but is now an abandoned folly that is slowly being overtaken by foliage and graffiti.

Built between 1817 and 1823, the fortress rests on the grounds of a former monastery on an elevated hill in Liège. It was originally built by the Dutch army, as Belgium had not yet been founded. However, during the Belgian revolution in 1830, the large fortification was taken over by Belgian forces who used the space as a barracks. It was large enough to house 3,000 troops, but was never filled to capacity. In the ensuing years, the fort was used as a prison by the Germans during both World Wars, and subsequently the buildings were used as a hospital by the United States. After over a hundred years in service, the huge complex was simply abandoned and continues to lay empty among a portion of land that is slowly being reforested.

Today the site is slowly being retaken by the surrounding foliage which creeps over the stonework like ancient ruins. Urban explorers and graffiti artists have also left their mark, making the abandoned Fort de la Chartreuse a relatively haunting gallery of ever-changing street art.