A public bath in an Iranian city was never only a place to wash: it was a social institution, with its own sequence of spaces, its water and heating system, and its architecture of vaults and half-light. The Sultan Amir Ahmad hammam, in the historic centre of Kashan, is among the best preserved. Visitors pass from the octagonal changing hall, ringed by low columns and platforms, into the warm and hot chambers, where turquoise and gold tilework and carved plaster survive on walls and vaults. Damaged and repaired over the centuries, the building owes much of its present appearance to nineteenth-century restoration. Its roof is a spectacle in itself: a rolling field of small domes, each pierced by a convex glass lens that drops a shaft of daylight into the rooms below. Filmed in 4K, above and below.
