Pongua Waterfall in Vietnam is truly breathtaking

Ban Gioc – Detian Falls (in Vietnamese: thác Bản Giốc, in Chinese: Détiān pùbù, Bǎnyuē pùbù 板約瀑布, 德天瀑布) are two waterfalls on the Quây Sơn River, in Chinese Guichun River, straddling the Sino-Vietnamese border, located in the Karst hills of Daxin County, Guangxi (Chinese side), and in Trùng Khánh District, Cao Bằng province on the Vietnamese side, 272 km (169 mi) north of Hanoi.^{[Ref 1]}
In Vietnamese, the two falls are considered as two parts of one waterfall with the sole name Bản Giốc. The two parts are called as: thác chính (Main waterfall) and thác phụ (Subordinate waterfall). Chinese texts sometimes name both falls from the Détiān falls on the Chinese side. During the summer rains the two waterfalls may join together.^[1]
The waterfall drops 30 m (98 ft). It is separated into three falls by rocks and trees, and the thundering effect of the water hitting the cliffs can be heard from afar.^{[Ref 2]}
It is currently the 4th largest waterfall along a national border, after Iguazu Falls, Victoria Falls, and Niagara Falls^[2] and was one of the crossing points for China’s army during the brief Sino-Vietnamese War. Nearby there is the Tongling Gorge accessible only through a cavern from an adjoining gorge. Rediscovered only recently, it has many species of endemic plants, found only in the gorge, and in the past was used as a hideout by local bandits, whose treasure is occasionally still found in the cliff-side caves.
A road running along the top of the falls leads to a stone marker that demarcates the border between China and Vietnam in French and Chinese. Modern disputes arose as there are discrepancies as to the correlating legal documents on border demarcation and the placement of markers between the French and Qing administrations in the 19th century.^{[Ref 3]}
Disputes regarding the border demarcation at this location were settled in 1999 Viet Nam-China Treaty on Land Borderline. Additional talks were held as late as 2009 to clarify the treaty.^[3] However, there are controversies regarding the border demarcation around the Falls. One faction^[who?] holds that the entirety of these falls belongs to Vietnam, and that the stone tablet had been moved there some time during or after the brief Sino-Vietnamese war of 1979.^[4] Also, these falls were not documented in any Chinese texts until recently.^{[citation needed]} To the southeast, the land dispute also along the Sino-Vietnamese border also includes Nam Quan Gate (Ải Nam Quan) which the Vietnamese claimed as well. Historically,^[5][6][7] Nam Quan Gate served as the border maker and entry point to Vietnam between Vietnam & China (hence there's also a Vietnamese historical saying,^[8] that Vietnam stretched from Mũi Cà Mau (Point of Ca Mau) to Ải Nam Quan).