Two main buildings in the Phra Maha Prasat Group were constructed during the reign of King Rama I; Dusit Maha Prasat and Phiman Rataya.

Phra Thinang Dusit Maha Prasat Hall

          Dusit Maha Prasat Throne Hall was constructed by King Rama I in 1789 on the site of an audience hall which was struck by lightning and burnt down during the early years of his reign.

          This throne hall is built in the shape of a cross. Its four wings are covered with four tiered roofs from the center of which rises a beautiful nine tiered prasat spire, the base of which is supported by four Garadas clasping Nagas. Its north wing leads to a window throne for formal outdoor recepyions which is now seldom used, the last occasion being when King Rama VI received the oath of fealty from the court after his coronation in 1911.

          Inside the hall are a throne inlaid with mother of pearl surmounted by a nine tiered white canopy and a bed inlaid also with mother of pearl, today used as an altar. In the south wings is a window in the form of a throne built by King Rama IV rather resembling King Narai's throne in the Palace at Lopburi. The Interior walls are painted with delicate designs.

          The hall communicates with an apartment called “Phiman Rataya”, situated in a garden. Dusit Hall is noted for its pure style and dignified simplicity. This hall was used for coronations, formal audiences and for the revision of the Buddhist scriptures. Since the death of King Rama I, it has been the place for lying in state. It is also used for certain royal functions like merit making. One of the special ceremonies that takes place here annually is the commemoration of coronation day. King Rama III used to give audience here to the court while he resided at Phra Maha Prasat during the renovation of his regular residence.

Phra Thinang Phiman Rataya Hall

          This is connected to the projection of Dusit Maha Prasat lengthwise towards the south. It is raised high above the ground, with pillared enclosures on three sides; east, west and south. The roofs is in three tiers of colored glazed tiles. The carved gable portrays Brahma mounted on a hamsa bird. The pediment like niches above the doors are in stylized arch form with peony patterns while those above the windows are in typical Thai design.

          King Rama IV built a garden to the right of it. Since space was limited he had the right wing pulled down and built a replica of Sumeru mountain for the tonsure ceremonies of his children when they reached puberty.

          Phiman Rataya used to be the sleeping quarters of kings when they took residence at the Maha Prasat. King Rama III stayed here for one whole year. Later during the reign of King Rama IV the remain of the Queen Mother lay in state here. So did the remain of King Rama VIII.

Phra Thinang Aphonphimok Pavilion

          On the wall around the Dusit Maha Prasat is Aphonphimok Pavilion, a lovely little pavilion in typical Thai style, built by King Rama IV as a disrobing pavilion. In the old days the king was carried on a palanquin to the shoulder high step of the pavilion where he alighted and removed his ceremonial hat and gown before proceeding to the Dusit Audience Hall. This pavilion was reproduced by King Rama V at Bang Pa In Summer Palace and a replica of it was exhibited at the World Fair in Brussels in 1958.

Phra Thinang Ratchakaranyasapha Pavilion

          To the south of Aphonpphimok pavilion is a small two storey building in bricks and mortar. The roof is covered with slate tiles. The gable is carved with Vishnu on Garuda surrounded by floral pattern and angles in adoration. The windows of the upper floor have pediment like niches above them while the windows of the ground floor are square in shape. It was built by King Rama V to hold meetings of his cabinet. At present it is used as the meeting hall of the King's Privy Council.