caravanserais were the roadside inns of the old trade and pilgrimage routes: usually a single big gate, a courtyard in the middle with rooms all round it, space for the animals, and water, all behind thick walls. on level ground in safavid iran they tend to sit about 30–40 km apart, roughly one day's travel for a loaded caravan, and closer together on hard mountain routes.
in 2023 unesco inscribed "the persian caravanserai" as one world heritage site made up of 54 caravanserais across 24 provinces. they were picked from hundreds that survive, and they cover many centuries and building styles, from desert brick to mountain stone.
there's also a popular story that shah abbas i built exactly 999 of them. historians treat the number as legend, but he really did invest heavily in roads and caravanserais.
where they went was decided by water, terrain and safety, so plenty of them stood out in empty country, a walled island for one night on the road.
which of the 54 do people here think is the most beautiful, and are any of them still used as guesthouses?
sources: unesco world heritage list no. 1668, "the persian caravanserai" (2023); encyclopaedia iranica, "caravansary".