Sri Thep Historical Park in Phetchabun province is expected to be recognised as a Unesco World Heritage site next week.
Phanombutr Chantharachote, director-general of the Fine Arts Department, said he has received a report from a Thai delegation to the World Heritage Committee's 45th extended session, which is taking place in Riyadh, in Saudi Arabia.
According to the report, the nomination of Sri Thep Historical Park as a World Heritage site is expected to be considered next Monday evening (local time) or Tuesday morning, Mr Phanombutr said on Wednesday.
He said he was confident the park, which has been nominated as a cultural heritage site, will be certified as a Unesco World Heritage Site as it meets the criteria set by Unesco.
Sri Thep Historical Park contains the Sri Thep ancient city and the Khao Khlang Nok and Khao Thamorat archaeological sites. "We are only waiting for official recognition from Unesco. Thais are eager for news as they have been waiting 31 years for a historic site to be listed as a World Heritage Site," he said.
The last site recognised by Unesco in 1992 was Ban Chiang Archaeological Site in Udon Thani. Two other World Heritage Sites in the cultural category are Sukhothai Historical Park and Ayutthaya Historical Park.
Sri Thep Historical Park contains historical structures, including a Khmer-style prang; Thailand's only pyramid-shaped hill, Khao Klang Nok; and a Buddhist stupa called Khao Klang Nai, famous for its Dvaravati-style bas-relief and small figurines around the structure's foundation.
The site, built around 1,700 years ago, is recognised both for its cultural and historical significance and has been listed as a national archaeological site since 1935.