Former inmates in Syria's largest and most notorious prison, Sednaya, recount the day they were thrown into a dimly-lit room, to find themselves standing ankle-deep in what appeared to be salt... but that was not it. Moments later came the second surprise, as they started stumbling on bodies, emaciated and half-buried in salt. The "salt rooms" were set up during the decade-old civil war as primitive mortuaries, to cope with the number of detainees who died of hunger or under torture. IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES