The Phra Thinang Amarin Winitchai Mahaisuraya Phiman (พระที่นั่งอมรินทรวินิจฉัยมไหสูรยพิมาน) or, in brief, thePhra Thinang Amarin Winitchai (พระที่นั่งอมรินทรวินิจฉัย) is the northernmost and forward building of the Maha Monthien buildings, It is also perhaps the most important. The throne hall was constructed in Thai style as a royal audience chamber, for receiving foreign ambassadors and for conducting important state businesses and ceremonies.[30][31]
In the front of throne sits another, called the Phuttan Kanchanasinghat Throne (พระที่นั่งพุดตานกาญจนสิงหาสน์). The throne is topped by the massive Royal Nine-Tiered Umbrella, an important symbol of Thai kingship. The different tiers represents the king's power and prestige which extends in eight directions: the four cardinal directions and the four sub cardinal directions. The final and ninth tier represents the central direction descending into the earth. These giant umbrellas usually deposited above important royal thrones, and out of the seven of which are currently in Bangkok, six of these umbrellas are situated within the vicinity of the Grand Palace and another is situated above the throne within the Ananta Samakhom Throne Hall of the Dusit Palace. The throne is made up of multi-layered squared platforms with a seat in the middle. The throne is used for the first royal audience of each king's reign and for annual birthday celebrations and other royal receptions. It was from this throne that King Rama II received John Crawfurd (the first British Envoy to Siam in almost 200 years) in 1821. Crawfurd was sent to Bangkok by the Governor-General of India Lord Hastings to negotiate a trade treaty.[29][31]