Buddhist monks collect their belongings at a flooded temple in the ancient city of Ayutthaya, Thailand, on October 7.
The 14th-century Siamese capital, listed as a UN World Heritage site, has been flooded for more than a week, according to the UN, which is sending a mission to Ayutthaya to survey the damage.
"This is the worst flood in our historical site in 16 years," Somsuda Leeyawanich of the Thai Fine Arts Department told CNN.
"We are very concerned that if the site is under water for more than 30 days, it may cause serious damage," she said. "The temples are over 400 years old."
Since July, at least 224 people have died in Thailand's worst flooding in 50 years, according to Reuters.
(See "Biggest Floods in History-Does Mississippi Make the List?")