For most of Bukhara's recorded history, power sat here. The Ark is a fortified town in its own right — palaces, a mosque, a mint, a prison and stables on a mound about 20 metres high — and people lived inside it from roughly the fifth century until 1920.

Below its gate lies the Registan, the open ground where the city met the state: proclamations, markets, crowds. Samarkand has a Registan too, a ceremonial square framed by three madrasas, with its own page in this guide; Bukhara's Registan mattered for what happened on it rather than for what was built around it. The Bolo-Hauz Mosque on its far side belongs to this space as much as it belongs to its own complex.