Prasat Phu Fai is twenty kilometers away from Amphoe Kantharalak to the Southwest, is built of redstone and rocks extracted from nearby mountains. The Prasat Phu Fai was a Khmer sanctuary in Thailand, in the province of Sisaket . Nothing is known of this edifice, situated at the top of a hill, and of which there are only heaps of ruins, and a pond. Perhaps it was one of the many chapels built by Jayavarman VII on the roads serving the Khmer Empire from the capital. This small site is located on top of a prominent hill (Phu Fai) located approximately halfway between Khun Han and Kantharalak, about 2 km north of Hwy. 3040. The hill is a distinctive basaltic monolith, easily visible from either Hwy 24 or Hwy 3040. In order to approach the site from either the north (Hwy 24) or from the south (Hwy 3040) you must traverse some poorly-maintained dirt roads. There are no signs indicating the site on any of the nearby roads or highways. The concrete road up the Phu Fai hill is fairly steep so visitors are advised to park at the base and walk up the road. Once you reach the top you must walk about 1 km on a concrete road, then turn right on an unpaved path to reach the site. A number of monks and female enunciates live on top of the hill. The prang has been completely disassembled for restoration, however that effort appears to have stalled. Thousands of bricks and hundreds of numbered laterite blocks are neatly stacked nearby, awaiting the completion of the restoration project. All lintels and carved sandstone artifacts have been removed and the prang has been disassembled, so the only thing remaining is the laterite foundation. The main lintel may be at Wat Supannarat. A stone wall, 1 - 2 meters tall, surrounds the site.