The neoclassic building of the museum was built in 1906, towards the end of King Rama V's reign. Designed by a Western architect, the three-storey concrete edifice is decorated with Greco-Roman motifs and reliefs with a dome-shaped tower topping its front hall. It was originally known as the John Sampson Store, selling Western clothing and custom-made suits.
In 1933, the Public Works Department took over the building as its headquarters. In 2001, King Prajadhipok Institute received the sanction of the Public Works Department for use of the building as the museum.
Permanent Exhibition Halls
Located on the 2nd and 3rd floors, the halls display the royal regalia and personal effects of King Prajadhipok (Rama VII) and photographs, documents and films concerning the King's life and the two historic events, in which the King played a leading role -- the 1932 Revolution and the Conferment of the first Constitution of Thailand.
Besides, there are a temporary exhibition room and a museum shop on the first floor.