Where Legend Meets Geography: Journey to the Sun-and-Moon Mountain (Riyue Mountain)

The Great Divide of the Plateau

Standing as a majestic natural fortress, Riyue Mountain (Sun-and-Moon Mountain) serves as the primary geographical and cultural gateway to the Qinghai-Tibet Plateau. Located in Huangyuan County, approximately 100 kilometers from Xining, it marks the definitive boundary between China’s monsoon and non-monsoon zones. To the east of this ridge lie the fertile, loess-covered agricultural basins, while to the west, the landscape transforms into the vast, rolling alpine pastures characteristic of the high-altitude nomadic world. This unique position makes the mountain a "fuzzy transition zone" where the farming civilization of the Central Plains meets the pastoral traditions of the highlands.

The Legend of the Broken Mirror

The mountain is most famous for its profound connection to the Tang Dynasty Princess Wencheng. According to enduring folklore, as the Princess traveled to Tibet in 641 AD to marry the Tubo King Songtsen Gampo, she climbed this peak and looked back toward her home. Overcome with homesickness, she dropped a "Sun-and-Moon Treasure Mirror" given by her father; the mirror shattered into two halves, one becoming a golden sun and the other a silver moon, which now lend their names to the mountain. Today, the Sun Pavilion and Moon Pavilion stand on opposite peaks, commemorating her historic journey and the cultural fusion it sparked.

A Historic Transit Hub

Historically, Riyue Mountain was a vital station along the Tang-Bo Ancient Road, facilitating the exchange of materials and diplomatic envoys between the Tang Empire and the Tubo Kingdom. It acted as a bustling trade hub where the agricultural products of the east were swapped for the livestock and medicinal herbs of the west. The mountain's name in Tibetan, "Dangar," actually translates to "White Cliff," highlighting the rugged geological features that have made it a strategic military and commercial pass for over a millennium.

Panoramic Vistas and the Backwards-Flowing River

Visitors standing atop the mountain are treated to a dualistic visual feast. Looking east, one sees a tapestry of terraced fields and rural hamlets, while turning west reveals the shimmering turquoise expanse of Qinghai Lake and the spiritual allure of the high plateau. Near the base of the mountain flows the Daotang River (Backwards-Flowing River), which, contrary to most rivers in China, flows from east to west. Legend says the river was formed by the tears of Princess Wencheng, flowing toward the west to accompany her into her new life in Tibet.