Phra Narai Ratchaniwet

King Narai came to the throne in 1656 and in 1666 ordered a palace, walls and forts built on the site of King Ramesuan's old palace, reportedly with French and Italian help. He spent eight or nine months a year in Lop Buri, hosted Chevalier de Chaumont's French embassy of 1685 with a banquet at the guest-reception hall, watched a lunar eclipse at Lop Buri with Jesuit astronomers on 11 December 1685, saw a Persian embassy arrive in early 1686, and La Loubère's second French embassy in October 1687.

Narai died in the Suttha Sawan hall here on 11 July 1688; Phetracha moved the court back to Ayutthaya and the palace was abandoned. In 1856 King Mongkut restored it and named it Phra Narai Ratchaniwet; his Phiman Mongkut hall group was finished in 1862, and under Rama V it served as the provincial hall. On 11 October 1924 Prince Damrong and Prince Naris opened the Lop Buri Museum in the Chanthara Phisan hall; the site was registered as a monument on 2 August 1936 (Royal Gazette vol. 53, part 24) and became a national museum in 1961.

The palace is rectangular and faces east, with walls about 5 m high, 11 pointed Persian-style gateways and about 2,000 lamp niches. The outer court holds a water tank fed by clay pipes from the Sap Lek reservoir, the twelve treasury stores, the guest-reception hall and the royal elephant stables; the middle court has the Chanthara Phisan and Dusit Sawan Thanya Maha Prasat halls and the Phiman Mongkut group; the inner court keeps the base of the Suttha Sawan hall and its four corner pools. In 2009–10 the west fortified wall and gates 1–2 were restored, and excavation uncovered the bases of six forts and six buildings.

The museum covers prehistory, Lop Buri-style art, the Narai era, King Mongkut's bedchamber and central Thai folk life, including nang yai puppets. The grounds open daily 09:00–16:30; the museum buildings Wed–Sun 09:00–16:00, closed Mon–Tue. Admission is 30 baht for Thais and 150 for foreigners, free for uniformed students, Thai seniors and monks; wheelchairs can be borrowed at the ticket desk. The King Narai Fair is held in mid-February — 13–22 February in 2026 — when visitors dress in Thai costume. Phone 036-411-458.