Shush, the modern town built over the ancient city of Susa, is one of the oldest continuously inhabited places on earth — people have lived here for at least 7,000 years. The archaeological site covers a vast area on the edge of town, and the small but worthwhile museum on site displays objects excavated from the royal palace and burial grounds, including the famous Code of Hammurabi stele (the original is in the Louvre; this is a cast).
The most dramatic structure is Susa Castle, a peculiar Gothic-style château built in 1897 by French archaeologists to protect their dig site and workers — it perches on top of the ancient citadel mound and can be seen from across the plain. The Tomb of Daniel, in the town itself, is marked by a distinctive spiralling cone-shaped tower. It is an active pilgrimage site and visitors of all faiths are welcome. Shush is about 100 km from Ahvaz; the road passes through flat farmland, unremarkable but for the sudden appearance of the castle on the horizon.