Prasat Phra Thep Bidorn (Royal Pantheon)
This building is the most important on the upper terrace and aligns with the entrance gate surmounted by a Thai-style stucco and porcelain crown. The two giants guarding this entrance are Indrajit in green with a bamboo shoot finial to his crown and Suryapop who is red with a similar crown. Behind may be seen the top of the Sawadee Sopha Gate (which is only opened on Buddhist holy days).
Prasat Phra Thep Bidorn was constructed by King Rama IV with the intention of housing the Emerald Buddha as he considered that the Ubosot was too low. However once the building was completed it was too small for royal ceremonies and, accordingly, other relics were installed instead. Later towards the end of the Fifth Reign a fire entirely destroyed the superstructure of the building necessitating its repair. Subsequently it housed statues of the five Chakri kings from the First to the Fifth Reigns. It acquired the name of Phra Thep Bidorn, translated in English as Royal Pantheon, during the reign of King Rama VI (1910-1925).

Phra Mondop (Library)
This building is situated to the rear of Phra Thep Bidorn on the same base. King Rama I ordered its construction to the north of the Ubosot to replace the former Phra Monthien Tham which was burnt. This earlier building had been constructed in the middle of a pond to prevent attack by termites - a common practice during the late Ayutthaya and early Bangkok period. Its purpose was to house the Tripitaka (Buddhist scriptures) which he had revised at Wat Mahathat in 1788 (the previous edition having been lost in the sack of Ayutthaya in 1767).
The library was extensively restored during the reign of King Rama III to commemorate the 50th anniversary of Bangkok. The cruciform building has a mondop-style roof. Originally it was on a higher base which raised it above the Ubosot. Accordingly when King Rama IV built Phra Thep Bidorn and Phra Sri Rattana Chedi, this building was seen to be too tall and was lowered.

Phra Sri Rattana Chedi
This is situated behind the Mondop on the same base. King Rama IV ordered its construction in order to house a Buddha relic. His original plan, as mentioned above, was that the Emerald Buddha would be rehoused in Prasat Phra Thep Bidorn, with the Mondop housing the Buddhist scriptures behind it and this stupa at the back, thereby echoing the classic arrangement of stupas in a straight line which had been characteristic of Buddhist architecture since the Sukhothai and Ayutthaya period.
The bell-shape of the chedi is based on the larger ones at Wat Phra Sri Sanphet in Ayutthaya. On each of the four sectors of the circular base are four protruding porches allowing access to the interior. Miniature chedis are placed on top of the porches. The chedi is covered with gold mosaic which was added by King Rama V and was originally ordered from Italy. The mosaic has recently been replaced.

The Ubosot (Chapel)
The Ubosot is located in the southern sector of the temple compound and is the principal building, being larger than all surrounding structures. To enter the Ubosot, the visitor must pass through two walls. These separate the building from the rest of the compound, thereby emphasizing its sacred nature. The wall is topped by double sema stones covered with gold leaf. Such stones traditionally designate a Buddhist building where the ordination of monks may be carried out.
The chapel was built during the reign of King Rama I in 1783 in order to house the Emerald Buddha statue which the King had taken from Vientiane in 1779. Previously it had been housed in the nearby Emerald Buddha hall on the Thonburi side of the river. Today this hall has been transformed into the chapel of Wat Arun on the opposite bank of the river. The Emerald Buddha was installed ceremonially on 22 June 1783.

The western side has three doors. The first (where you enter the temple compound) aligns with the rear of the Ubosot and is guarded by two giants whose crowns are topped by cockerel’s tails. The white giant, Chakrawat with four heads and eight arms is paired by Asakornmarsa who is dark purple and has a double tier of heads. The second aligns with the western side of Phra Sri Rattana Chedi.The white giants Sahasadeja has one thousand heads arranged in five tiers and two thousand arms. He stands with Tosakanth who is green. He has three tiers of three heads and one on top. His crown is topped with a chai. The thirds door aligns with the northern side of Phra Sri Rattana Chedi and is once again guarded by giants with cockerel tail crowns-the navy coloured Virunchambang and his companion the pale mauve Mayarap.