Cambodia's third-largest city was also an ancient Khmer center of culture and power on the Mekong River, and it has a pre-Angkorian temple, Wat Nokor. (Sadly, the temple itself is in a state of disrepair and the $2 entry fee unmerited.) Just outside town are the twin temple-topped hills, Phnom Pros and Phnom Srei (included in the price). Ask a local guide to explain the interesting legend surrounding their creation. In the ecotourism village of Cheungkok, about 5 km (3 miles) south of town, you can see silk making, carving, and other traditional crafts in progress and also buy the wares directly from villagers. All profits are reinvested in the village.
Kampong Cham can be visited in a few hours, but with Cheungkok it is an all-day trip.