There are many worth exploring Historical sites in Thailand, especially the Historical parks that are also significant ancient sites throughout Thailand which can be compiled to 5 historical parks that should not be missed.

Sukhothai Historical Park: an area of ​​the Historical Park which was the ruling centre of the Sukhothai Kingdom 6-7 hundred years ago, covering more than 70 square kilometres. The major city is in the Sukhothai city wall which is about 2 kilometres long and 1.6 kilometres wide. There are about 70 important monuments that still occur traces of royal palaces and temples. The largest temple is Wat Mahathat where more than 200 pagodas are located. 

Open daily from 06.00-21.00 hrs. (Last tickets at 18.00 hrs.) Note: From about 19.00-21.00 hrs, there will be astonishing lighting at the historic site. The admission fee is only 10 THB for Thais and 40 THB for foreigners. 

Kamphaeng Phet Historical Park: Kamphaeng Phet is a province nearby Sukhothai where many ancient sites in the same era are located as a part of Kamphaeng Phet Historical Park. In that era, Kamphaeng Phet was a major outpost city of the Sukhothai Kingdom. The historical park covers both inside and outside the city walls. There are a total of 20 archaeological sites in the city wall, such as Wat Phra Kaew, Wat Phra That, the ancient temple or holy water pond, Shiva shrine, and Wat Klang Nakhon, etc. Each one fully reveals city planning in the past. 

Open daily from 08:30 - 16:30 hrs. The admission fees are only 10 THB for Thais and 30 THB for foreigners. 

Phimai Historical Park, Nakhon Ratchasima: Move to the northeast, one of the most popular historical parks in this area is Phimai Historical Park which is about 60 kilometres from Nakhon Ratchasima city centre. In the past, this area is the location of Phimai City under the reign of King Suryavarman I where he established Phimai Sanctuary by Khmer art style surrounded by walls and ditches during the 16th Buddhist century or 1,000 years ago. 
 
Open daily from 7.00 - 18.00 hrs. The admission fees are 20 THB for Thais and 100 THB for foreigners. 

Phanom Rung Historical Park, Buriram: it is another significant historical symbol in Isan (northeastern Thailand).  Phanom Rung Historical Park in Buriram is about 77 kilometres south of Buriram’s city centre. Phanom Rung is located on an inactive volcano in the past. There have been several constructions in the past since the 15th-18th Buddhist century approximately. It is one of Thailand’s most well-known ancient sites influenced by Khmer culture. The highlight is on 2-4 April and 8-10 September every year, when the sun rises and shines through all the 15 gates of the castle creating a stunning combination of buildings and nature. 

Open daily from 06.00-18.00 hrs. The admission fee is 20 THB for Thais and 100 THB for foreigners. 

Ayutthaya Historical Park: Returning to the central region, there is Ayutthaya Historical Park located on the island of Ayutthaya. In the past, it was the location of the 400 years old, the Ayutthaya Kingdom. The park consists of 425 archaeological sites, starting from the royal palace to various large and small ancient temples with an area of ​​more than 1,810 rai (2,896,000 square meters), so visitors can explore all day long. 

Open daily from 8:00 - 18:00 hrs. The admission fee is 10 THB for Thais and 40 THB for foreigners.