Kashan's greatest treasures are its traditional merchant houses, and no visit is complete without spending time inside at least two or three of them. The Tabatabaei House is the grandest — four courtyards, soaring windtowers, and stucco ceilings of extraordinary delicacy. The Boroujerdi House next door was built to impress a single bride and outdoes even its neighbour in the ambition of its painted decoration. Both are within a few minutes' walk of each other in the old merchants' quarter.
The Agha Bozorg Mosque is the city's finest religious building — a sunken courtyard mosque and madrasa from the late 18th century whose cool geometries are a perfect counterpoint to the exuberance of the houses. The Bazaar of Kashan runs through the old city in a series of vaulted corridors connecting the mosque, a caravanserai, and the surrounding streets. It remains a working bazaar rather than a tourist arcade.
The Sultan Amir Ahmad Bathhouse in the southern part of the old city is one of the best-preserved traditional hammams in Iran — its tiled domes and star-shaped skylights are best appreciated from the roof as much as from inside. Outside the city, Fin Garden is the oldest surviving Persian garden in Iran, a UNESCO World Heritage Site, and worth a half-day. The prehistoric mound of Tepe Sialk, on the city's western edge, is one of the oldest known settlements in Iran and an easy stop for anyone interested in the deeper past.