Orkhon Valley and Karakorum

Long before Chinggis Khaan, the Orkhon Valley was a seat of steppe power, and UNESCO records remains here from the 6th century onwards. At Khöshöö Tsaidam, rulers of the Second Turkic Khaganate raised memorial steles in 732 and 735 to Prince Kul Tigin and his brother Bilge Khagan. Their runic texts, found in 1889 and deciphered in 1893, are among the earliest known Turkic writing. From about 745 the Uyghurs built Ordu-Baliq, now called Khar Balgas, a capital of more than 30 square kilometres that flourished until the Yenisei Kyrgyz sacked it in 840.

Chinggis Khaan chose the valley for his residence in 1220, and his son Ögedei walled the growing city and began a palace in 1235. Karakorum became a cosmopolitan capital: the Flemish friar William of Rubruck, who arrived in 1254, described its markets, temples and mosques, and a silver tree fountain made by a Parisian goldsmith that poured drinks for Möngke Khan's guests. Khubilai moved the seat of power to China in the 1260s, and Ming forces destroyed the city in 1388. Since 1999 Mongolian and German archaeologists have shown that the building long taken for Ögedei's palace was in fact a large Buddhist temple.

In 1585 Abtai Sain Khan, ruler of the Khalkha Mongols, ordered a monastery built beside the ruins of Karakorum, and its builders reused the old capital's stone. Erdene Zuu, the Hundred Treasures, grew inside a square wall about 400 metres a side lined with 108 white stupas, and at its height held dozens of temples and up to 1,000 monks. During the purges of 1937 to 1939 all but three of its temples were destroyed. The survivors were kept as a museum, and since 1990 Erdene Zuu has again been a working monastery, with monks at prayer in the Tibetan-style Lavrin temple.

Abtai's great-grandson Zanabazar, later Mongolia's first Jebtsundamba Khutughtu, was 14 when in 1648 he chose a rocky summit on Shireet Ulaan mountain, south-west of Kharkhorin, as a retreat. At Tövkhön he worked as a sculptor and, by tradition, devised the Soyombo script. The hermitage was wrecked in 1688 and again in the 1930s, and religious life resumed in 1992. Back in Kharkhorin, traces of the imperial city lie in the grass, among them a granite turtle that once carried an inscribed stele.

UNESCO inscribed the Orkhon Valley Cultural Landscape in 2004, protecting 121,967 hectares of grassland on both banks of the river and stressing that its pastures are still grazed by herders moving between seasonal camps, as their predecessors did around the old capitals. The Orkhon rises in the Khangai Mountains and runs 1,124 kilometres, Mongolia's longest river, before joining the Selenge on its way to Lake Baikal. Upstream of Kharkhorin, ancient lava flows left basalt plateaus, and at Ulaan Tsutgalan, the Orkhon Waterfall, the water drops about 20 metres into a dark gorge.

The valley faces real pressures. Mongolia's reports to UNESCO cite drought, desertification and declining plant diversity in heavily grazed areas, and placer gold mining damaged rivers across central Mongolia in the 2000s before national laws banned mining at headwaters and in water protection zones. Growing tourism brings more ger camps and traffic, and a planned new city near Kharkhorin has raised concerns among Mongolian heritage specialists. Travelling with local guides, staying in licensed camps and keeping to existing tracks all help limit the impact.