Chon Daen district Tuesday announced the discovery of two "coral mountains", which are being touted as new tourist attractions.
District chief Chartchai Petcharadhburanin said the survey team stumbled upon two limestone mountains in Ban Sappakai, 3-4 kilometres off Chon Daen-Nong Phai road.
The mountains are believed to have once been under the sea millions of years ago, he said. They covered an area of almost 1,000 rai (160 hectares) and had off-white coloured stripes with patterns similar to underwater coral reefs.
There are numerous caves which have intricate limestone formations. Many rare wild plant species can be spotted in rock crevices.
Mr Chartchai said experts would be asked to study the rocks to determine the mountains' origin before opening the site to tourists.