The original name of Kampong Thom was "Kampong Pus Thom" or the Kampong of the big snakes (Kampong is a peer, a landing on a river). This name was derived from a couple of big snakes that were said to live in cave at the Sen river and which people saw on the holy Buddhist days. The French during the colonial times abbreviated the name of the city to "Kampong Thom" or big Kampong and named the province after it when they divided the kingdom into provinces.
Kampong Thom is the base for excursions to the important archaeological site of Sambor Prei Kuk, the ancient capital of Chenla. Just 35 km away from the city, this site can only be reached by travelling down an unpaved road. Approximately 170 temples from the pre-Angkorian period (7th century) can be found here surrounded by lush forest.