A long cliff named Pha Taem is the centrepiece of awesome but unheralded Pha Taem National Park, which covers 340 sq km along the Mekong River. From the top you get a bird's-eye view across the Mekong into Laos, and down below a trail passes prehistoric rock paintings.
The wilderness north of the cliff holds more ancient art, some magnificent waterfalls (all flowing June to December) and scattered scattered rock fields known as Sao Chaliang, which are oddly eroded mushroom-shaped stone formations.
Many Thais come here for the sunrises. Pha Cha Na Dai cliff, which requires a high-clearance vehicle to reach, serves Thailand's first sunrise view of each day. But Pha Taem cliff is only about one minute behind.