The Zindon was the Bukharan emirs' prison, located just outside the Ark citadel, and its most notorious feature was the korak — the "Bug Pit." This was literally a deep well, roughly six metres down, into which condemned prisoners were lowered on ropes and left in darkness with scorpions, lice, and rats. It was not a metaphor.
Today the Zindon is a small museum. You can descend into the reconstructed pit (now clean and safe) and see the mannequins illustrating the conditions endured by its most famous inmates. The story of Stoddart and Connolly — two British officers dispatched to negotiate with the emir during the Great Game and executed after months of imprisonment — is told through displays upstairs. The museum is grim, compact, and genuinely gripping. It provides essential context for understanding the Ark that towers next door.