Nong Ya Plong Hot Spring
(น้ำพุร้อนหนองหญ้าปล้อง เพชรบุรี)
Phetchaburi
Nong Ya Plong Hot Spring, Surrounded by mountainous landscape, the Nong Ya Plong Hot Springs is found in a stream in the area full of Kaeng Krachan Formation, Permo-Carboniferous rocks composed of quartzite, slate and hornfels rocks and phyllite pebbles. In addition, found to the east of the hot springs is Kaeng Krachan Formation, mostly made up of conglomeritic sandstone along with siltstone and conglomerate. Furthermore, Cretaceous granite batholiths are found standing like a high mountain range to the south and the west of the hot springs. Most of them are grey and have a hard porphyritic texture. Also, aplite and pegmatite as well as quartz veins are found throughout the granite rocks. Moreover, there are faults around the hot spring area. The major ones are the NW-SE fault, the NE-SW fault and the E-W fault. Located to the north of the hot springs and intersecting the stream, the E-W fault may play an important role in creating the hot springs.

The Nong Ya Plong Hot Springs physically consists of warm springs found between a public land and National Forest. It has four springs lining up on a north to south axis. Each of them has a diameter of about three to five metres and a depth of around 30 metres. Water normally flows from the northernmost to the southernmost springs and is also stored. In addition, yellow-green algae are found in the hot springs. Furthermore, the Petchaburi Provincial Administrative Organisation constructed a 200-metre-long pipe to convey hot water from the springs to newly-built mineral water bathrooms.