Geosites of Hinboun Geopark
The fengcong karst massifs, pinnacle karst, poljes, and magnificent caves within the Hinboun Geopark constitutes a karst landscape of outstanding geomorphological significance on a global scale. Today, the Geopark comprises 18 geosites, including five sites of international geological significance, which together illustrate the exceptional geological diversity and heritage of the territory.
KONGLOR-NATANE RIVER CAVE
The Konglor–Natane River Cave geosite is recognized as one of the great caves of the world and as the world's longest navigable cave river. The Hinboun River flows underground for 7.5 km through Konglor Cave, and the magnificent cave river is navigable by longtail boat throughout the year, making it a unique tourism experience. At the upstream end of the cave, dissolution has created a maze of phreatic rifts, and subsequent water flow has enlarged the most efficient route into a single river passage.
NAMNONE CAVE
The Namnone Cave geosite is recognized for its large passage size and for its enormous volume of infilling sediments. The cave has a main streamway that flows for 6 km through the karst massif, with a water-filled siphon at the mid-point. It has a flowing river during the wet season and ceases to flow early in the dry season. The main passage averages 37 m in height and 40 m in width, with maximum dimensions of 50 m high and 73 m wide. The entrance portal, overlooked by a cliff several hundred meters high, has been opened to visitors and offers a striking impression of the immense scale of this cave.
PINNACLE KARST OF PHOU PHA MARN
The Pinnacle Karst of Phou Pha Marn (The Rock Viewpoint) geosite features spectacular, sharp-edged pinnacles of international significance. Pinnacle karst is a spectacular, small-area landform found mainly in the humid tropics and subtropics. The pinnacle karst at Phou Pha Marn rivals those at Gunung Mulu in Borneo and Mount Kaijende in Papua New Guinea, and is accessible to the public thanks to a 600-metre boardwalk that extends over the site.
NATANE POLJE
The Natane Polje geosite is of international significance because of its size (43 km²) and its enclosure by high, steep limestone and sandstone cliffs. While larger poljes exist in the Dinaric karst of Europe, Natane Polje is comparable in size to the Cerknica Polje in Slovenia, one of the largest and best-known poljes in the world. Its nearly circular shape and central location, surrounded by impressive karst cliffs, make it particularly well suited for visitor education.
NAKOUAN KARST LANDSCAPE EVOLUTION
The Nakouan Karst Landscape Evolution geosite is characteristic of the Hinboun Geopark, featuring karst massifs almost completely bordered by bare limestone with very steep slopes or high cliffs rising up to 500 m above intervening poljes and plains. The karst massifs have been dissected by karst processes into a polygonal relief, similar to an enormous egg tray, where numerous deep depressions are surrounded by residual conical hills (fengcong). These fengcong massifs are comparable in size and evolutionary stage to those at the Hin Nam No World Heritage Site in eastern Khammouane Province, which is recognized for its Outstanding Universal Value.
Here is a list of the 18 geosites classified by type and significance:
| Nø | Name | Type | Significance |
|---|---|---|---|
| 1 | Konglor-Natane River Cave | Geomorphology & Hydrogeology | International |
| 2 | Pinnacle Karst of Phou Pha Marn (The Rock Viewpoint) | Geomorphology | International |
| 3 | Namnone Cave | Hydrogeology | International |
| 4 | Tham Pha Mue Prehistoric Rock Art | Geomorphology & Archeology | National |
| 5 | Tham Praya Mengvanh Historical Site | Geomorphology & Archeology | National |
| 6 | Ta Teukkheuk Karst Tower | Stratigraphy | National |
| 7 | Namsanam Waterfalls | Geomorphology | National |
| 8 | Siltstone-Limestone Transition Zone of Phou Pha Marn | Stratigraphy | Local |
| 9 | Phou Hai Karst Landforms Viewpoint | Geomorphology & Landscape reading | Local |
| 10 | Tham Phakhong Buddhist Temple | Geomorphology & Archeology | Local |
| 11 | Houaynamsai Karst Spring (Blue Lagoon) | Hydrogeology | Local |
| 12 | Pha Tham Khouay Tectonic Dipping Beds | Tectonic | Local |
| 13 | Natane Polje | Geomorphology | International |
| 14 | Phabane Karst Tower | Geomorphology | Local |
| 15 | Khikeo Karst Tower | Geomorphology | Local |
| 16 | Nakouan Karst Landscape Evolution | Geomorphology | International |
| 17 | Namuang Polje Hydrosystem | Hydrogeology | Local |
| 18 | Nadan-Nasida Karst Landscape Viewpoint | Geomorphology & Landscape reading | Local |