Ancient Palace was originally built by King U-Thong During the reign of King Barom Trailokkanat and later kings, several new buildings were added, including Wat Phra Si Sanphet. Notable buildings are wihan Somdet Pavilion, Sanphet Prasat Pavilion, Suriyat Amarin Pavilion, Chakkrawat Phaichayon Pavilion, Banyon Ratanat Pavilion and The Tri Muk Building. These pavilions were completely destroyed in 1767, leaving only brick foundations, porticoes and walls. The Tri Muk Building, a wooden structure with a brick foundation, was rebuilt in its original style mmand of King Chulalongkorn in 1907.