Situated outside the Kampaeng city in an area of Nakorn Chum old city, Pom Thung Setthi fortress was built in square shape made of laterite with a length of 84 meters per side and a height of 6 meters. It was assumed to be built in Ayutthaya period by the European style which influenced to Thailand in the reign of King Narai.
The fortress was fortified by battlements and enclosed by parapets with openings for firing guns. Watchtowers were constructed at the four corners.