Övörkhangai Province in the context of Ötüken

The Orkhon River (/ˈɔːrkɒn/ OR-kon) is the longest river in Mongolia.

It rises in the Khangai Mountains in the Tsenkher sum of Arkhangai aimag at the foot of the Suvraga Khairkhan mountain.From there, it crosses the border into Övörkhangai aimag and follows the upper Orkhon valley in an eastern direction until it reaches Kharkhorin. On this stretch, very close to the Orkhon, the Ulaan Tsutgalan river features a waterfall, ten metres (33 ft) wide and twenty metres (66 ft) high, which is a popular destination for tourists.

Karakorum (Khalkha Mongolian: Хархорум, Kharkhorum; Mongolian script:ᠬᠠᠷᠠᠬᠣᠷᠣᠮ, Qaraqorum) was the capital of the Mongol Empire between 1235 and 1260 and of the Northern Yuan dynasty in the late 14th and 15th centuries. Its ruins lie in the northwestern corner of the Övörkhangai Province of modern-day Mongolia, near the present town of Kharkhorin and adjacent to the Erdene Zuu Monastery, which is likely the oldest surviving Buddhist monastery in Mongolia. They are located in the upper part of the World Heritage Site Orkhon Valley.

The Erdene Zuu Monastery (Mongolian: Эрдэнэ Зуу хийд, romanized: Erdene Zuu khiid) is probably the earliest surviving Buddhist monastery in Mongolia. Built in 1585, it is located in Kharkhorin, Övörkhangai Province and is now included within the Orkhon Valley Cultural Landscape World Heritage Site. The monastery is affiliated with the Gelug sect of Tibetan Buddhism.

The Ongi River (Mongolian: Онги гол, Chinese: 翁金河, 翁金高勒) flows from the southeastern slopes of the Khangai Mountains in Övörkhangai Province for 435 kilometres or 270 miles through the endorheic Ongi River Basin in Mongolia and through the aimag capital Arvaikheer. In some particularly wet years, it used to empty into Ulaan Lake in north central Ömnögovi Province, in most years it dries up earlier.

In recent years it has been additionally threatened by 37 mining operations within the basin, but successful pressure by Tsetsgeegiin Mönkhbayar and the Ongi River Basin Movement helped convince 35 of the operations to cease explorations and harmful activities in the region. The water and groundwater in this area may be contaminated with mercury and cyanide from the mining industry.