Bangkok. Sprawling urban growth and water management problems are threatening conservation efforts at Thailand's ancient city of Ayutthaya, experts say.
The Unesco World Heritage site located some 80 kilometers north of the capital, Bangkok, was once among the world's wealthiest cities and a major trading port from the 14th to 18th centuries.
Today, the city attracts tourists from around the world who come to admire the ruins and stone Buddha statues at Ayutthaya, once the ancient capital of Thailand, then known as Siam.
However, poor urban planning and its impact on water management in the low-lying area pose a threat to the historic park, said Montira Horayangura Unakul, national professional officer with Unesco's Culture Unit.
"Half the island is protected as a historic park and is also a world heritage site and the eastern half is where a lot of the modern development has taken place," Montira told Reuters in a telephone interview.
Rapid development has fueled concern over the area's capacity to defend against floods.
Devastating floods in Thailand in 2011, which killed more than 900 people and cost billions of dollars, hit Ayutthaya. Dozens of temples were inundated for weeks, although most suffered little damage.
"Once the waters receded there didn't seem to be too much damage," said Montira.
"However, after that we found residual effects for example to mural paintings."
A lack of knowledge about traditional materials used at some sites is another problem that besets Ayutthaya and other heritage sites, including the awe-inspiring Angkor Wat temple complex in neighboring Cambodia.
"An issue we are trying to address now is knowing what the ancient materials used in Ayutthaya were and what the composition of them was," Montira said.
Thailand held an international conference, in collaboration with Unesco, last month to discuss conservation of brick monuments at the site.