The museum is located in the building of the Ministry of Defense. The structure is an exemplary illustration of the Neo-Palladian architectural style from the Neo-Classical Age which was popular during the reign of King Rama V. The built heritage has been listed as a conservation building with highly commended architectural and historical value. It carries symmetrical gables and tall columns, and the building looks elegant with elaborate stucco. An open-air museum sits in front of the building, displaying forty ancient canons which played a significant role in Thai history. They are arranged according to their age, ranging from the Ayutthaya Period to the Rattanakosin Period.