The K50 Waterfall (; also known as Hang ÃÂn Waterfall, ) is a waterfall in in commune, Gia Lai province, in Vietnam's Central Highlands. It lies in the upper drainage basin of the Côn River and is about by road from Pleiku.
The waterfall drops about , with some published figures reaching . Reported widths range from roughly , depending on season and viewing position.
K50 forms a single drop over an arched rock ledge, producing a curtain-like fall. A recessed cavity behind the falling water is known locally as hang ÃÂn ("swallow cave").
The name "K50" is often linked to the waterfall's approximate height, while "Hang ÃÂn" refers to the recess behind the water and local accounts of swallows in the area.
K50 lies in the core zone of and is managed by the reserve's management board. The site lies near the administrative boundary with An Lão district (historically in Bình ÃÂá»Ânh province, now Gia Lai). Other published accounts place it in Sán Lang and ÃÂak Roong communes of K'Bang district. A 2004 overview document for the nature reserve (summarizing surveys conducted in 1999) lists "Waterfall 50" at roughly high among the waterfalls in the upper Côn River basin.
Resolution 202/2025/QH15 reorganized provincial-level administrative units, merging Bình ÃÂá»Ânh province and Gia Lai province under the name Gia Lai. Resolution 1664/NQ-UBTVQH15 merged Sá Pai commune and Sán Lang commune into a new commune named Sán Lang; the resolution provided for the new unit to begin operating from July 1, 2025.
K50 Waterfall lies in in the Kon Ha Nung highlands, on headwater streams of the Côn River system.
Remote-sensing studies of the Kon Ha Nung Plateau describe basalt-derived plateau surfaces and low-to-mid-elevation mountains developed on granite. A protected-area profile describes older rock units in the reserve, including Precambrian formations dated to about 1.4âÂÂ2.5 billion years. The upper basin has many short streams and waterfalls.
Kon Ha Nung Plateau has a tropical monsoon highland climate. Mean annual temperature has been reported around , with annual rainfall commonly given as roughly . A drier period is described as JanuaryâÂÂApril and a rainy period as MayâÂÂDecember, with headwater flows varying accordingly.
Headwater streams in the reserve feed the Côn River, which drains east toward the coastal lowlands historically associated with Bình ÃÂá»Ânh province. A basin-scale technical report gives the KoneâÂÂHàThanh system at about , and describes the Kone main stem as about long measured from the river mouth to its source. Vietnam's inter-reservoir operating rules for the KônâÂÂHàThanh system define an annual flood season from 1 September to 15 December and a dry season from 16 December to 31 August. Lower flows during the drier months improve access and visibility of the arched ledge and the recess behind the fall.
K50 is situated in evergreen forest habitats within Kon Chu Rang Nature Reserve, part of the core zone of the Kon HàNừng biosphere reserve designated by UNESCO in 2021 under the Man and the Biosphere Programme and the World Network of Biosphere Reserves. A provincial portal for the biosphere reserve gives a total area of , including core, buffer, and transition zones; Kon Chu Rang Nature Reserve lies within the core zone.
A 2004 overview document (summarizing a 1999 survey) records 546 species of vascular plants in the reserve, along with 62 mammal species and 169 bird species. A scientific summary report gives 413 vertebrate wildlife species and 211 insect species and lists threatened plant species and conservation-priority vertebrates in the area.
Two new species of Lasianthus (family Rubiaceae) have been described from Kon Chu Rang Nature Reserve. Specimens were recorded at elevations of roughly along routes between waterfalls in the reserve, including routes linking K50 with other waterfalls and access trails. Spray from the waterfall can create heavy mist, and rainbows can appear on sunny mornings under suitable viewing conditions.
Kon Chu Rang Nature Reserve was established in 1986 (Decision No. 194/CT) with an area of about ; a 1999 investment project defined zones for strict protection, ecological restoration, and buffer areas. A 2004 overview document gives the reserve area as about and describes zoning and buffer areas at the time of compilation.
Kon Chu Rang and Kon Ka Kinh National Park form part of the core area of the Kon HàNừng biosphere reserve designated by UNESCO in 2021. Identified threats include hunting and wildlife trade; logging and extraction of forest products; agricultural expansion; infrastructure development and resource extraction; and forest fires; monitoring and enforcement are described as priorities for biodiversity protection.
Kon Chu Rang forms an ecotone between the eastern and western slopes of the Annamite Range (), with high forest cover and a system of streams and waterfalls in the Côn River headwaters basin.
Bahnar folklore in the region includes stories associated with waterfalls; some accounts link But Jai to Hang ÃÂn Waterfall. The waterfall is promoted as a forest trekking destination in the area.
Access routes run from Gia Lai via main roads to the nature reserve gate, followed by a forest walk or hiking segment to reach the base of the waterfall. During the dry season, rock features and the arched recess behind the water are more visible; storms increase hazards such as slippery terrain and falling branches.
On July 3, 2024, a 55-year-old female tourist died after being struck by a falling tree while traveling by motorcycle on the access road to the waterfall during stormy weather. After the incident, safety measures on forest routes to tourist sites in the area were reviewed.