The waterwheels of Hama are one of the most iconic images of Syria. With their history of lifting water and supplying it into aqueducts to be used for irrigation since the Middle Ages, they should be a shoo-in whenever they get nominated, as every WHC loves a bit of water management. In addition to the technology, there's a whole traditional system of skilled noria carpenters behind it as well.
On the ground, however, they are disappointing. At least when you visit out of season, as I did: the wheels only turn in winter and spring, as only then is there enough water. The Orontes River in September was almost empty, except for the heaps of plastic trash that are unfortunately so common in Syria. It is also hard to see the large wooden wheels up close or to get to good viewpoints to take pictures. The best point in the city center is from the bridge.
Hama Els Slots
We saw five of them in the city center; the other twelve or so remaining ones are scattered around the countryside near Hama. According to my guide, they are more impressive as they have a finer natural setting.
Hama itself has preserved its small historical urban zone quite well (at least that part that was left after the 1982 anti-Assad uprising, which was brutally ended), and you can follow the trajectory of the aqueducts. All but one of the waterwheels have survived the war (one was burned deliberately in 2014), but they suffer from a lack of maintenance. The Bradt guide to Syria of 2006 advertises Hama as a pleasant town to stay the night, but we spent maybe half an hour there, including sitting down for the local snack Halawet el-jeben ("sweetness of the cheese", a mix of semolina, cheese and clotted cream).