Wat Mahathat in Ayutthaya Historical Park

The Ayutthaya historical park covers the ruins of the old city of Ayutthaya, Thailand. The city of Ayutthaya was founded by King Ramathibodi I in 1350 and was the capital of the country until its destruction by the Burmese army in 1767. In 1969 the Fine Arts Department began with renovations of the ruins, which became more serious after it was declared a historical park in 1976. The park was declared a UNESCO World Heritage Site in 1981. Thirty-five kings ruled the Ayutthaya kingdom during its existence. King Narai (1656 CE to 1688 CE) not only held court in Ayutthaya but also from his palace in the nearby city of Lopburi, from where he ruled 8–9 months in the year.

Built during Ayutthaya period, Wat Mahathat temple was then known as Wat Salak. Soon after Bangkok was established as the capital of Siam,[3] the temple became strategically situated in between the newly-built Grand Palace and Front Palace (residence of the vice-king). As a result, the temple was used for royal ceremonies and funerals. Throughout the past two centuries, the temple has been renovated and elevated in status by many Thai kings and royalties. It became the Wat Mahathat of Bangkok in 1803 and was given its current name in 1996. The temple is also home to Vipassana Medidation centre.

Angkor Wat, Angkor Thom and Ta Prohm in Siem Reap

Angkor Wat was built for King Suriyavarman II in the 12th century as his state temple and capital city.  As the best preserved temple, Angkor Wat is the only is the only one to have remained a significant religious center since its foundation- first Hindu dedicated to god Vishnu.  The temple has become a symbol of Cambodia   appearing on its national flag and is the country's prime attraction to visitors.  

Angkor Thom was the last and most enduring capital of the Khmer empire.  It was established in the late 12th century by King Jayavarman VII.  It covers an area of 9 square kms.  One inscription found in the city refers to Jayavarman as the groom and the city his bride.  The Bayon was built int eh early 13th century as the official state temple of the Mahayana's Buddhist Kign Jayavarman VII.  Its most distinctive feature is the multitude of serene and massive stone faces on many towers.

Ta Prohm is originally callled Rajavihara and is located 1 kilometer east of Angkor Thom.  Unlike many Angkorian temples, Ta Prohm has been left in much the same condition in which it was found.: the photogenic and atmospheric combination of trees growing out of the ruins and the jungle surroundings which have made it one of Angkor's most popular temples which was created by King Jayavarman VII in 1186 AD.