The multi-year civil war in Syria has left hundreds of thousands of people dead, and turned what was once a vibrant country into a wasteland of death and devastation.
In Aleppo, once home to 1.8 million people, a city thousands of years old had been reduced to rubble.
Photographers have collected before and after images of the city. Side-by-side, they show just how damaging the civil war has been.
See the images below, via BBC.