THE majestic beauty of the Qilian Mountains took us totally by surprise. We were traveling on the highway from Gansu Province to Qinghai Province and Qilian was only supposed to be an obstacle to be overcome en route. No-one had expected we would spend time sightseeing here.
The drive toward the range had already been fantastic. The autumn sky was clear; the air fresh and dry; there weren't many vehicles on the highway - really rare in China, especially considering this was the National Day holidays.
After spending a few days in Gansu's desert region, we were heading to Qinghai when we came upon ranks of tall poplar trees flanking the road, half their leaves still green, half in autumn gold.
Everyone in our minibus asked to stop to get photographs of the scene and breathe the fresh air. The view was stunning: the highway stretching into the far horizon, flanked by beautiful trees beneath a bright blue sky.
Plains extended on both sides, seeming to spread to the other side of the world, where they met with towering mountains ranges, indistinct in haze.
Before us were only small haystacks dotted on the grasslands and the tall trees rustling in their autumn splendor.
But a second glance to where the highway met the horizon revealed something else; in the far distance loomed the Qilian Mountains.
The dark grey mountains look like a giant dragon, lying peacefully as it has been for millions of years, its towering peaks topped with pure white snow.
What we were seeing is just a tiny part of the huge Qilian range. The mountains stretch from the south of Dunhuang in Gansu Province, running 800 kilometers to the southeast, forming the northeastern escarpment of the Qinghai-Tibet Plateau and the southwestern border of the Hexi Corridor in Gansu Province. The Qilian Mountains also provide a natural border between Qinghai and Gansu.
We drove through Biandukou, a pass in the range that links Gansu's Minle County in the north and Qilian County in Qinghai to the south.
At an altitude of 3,500 meters, this is one of the best sightseeing spots before being fully embraced by the huge mountains. A viewing terrace built halfway up the peak offered a bird's-eye view of the trees and newly-surfaced highway below.
Later we learn that Biandukou was once one of the most important military spots in the Qilian Mountains, in the past, the only pass on the Silk Road to enter Gansu Province from Qinghai.
The Emperor Yang of the Sui Dynasty (AD 581-618) stopped at Biandukou during his tour to the west in AD 609. His army was trapped here during a blizzard - although it was June in the lunar calendar.
The emperor's sister died and was buried here. However, the Emperor Yang survived and arrived in Zhangye in Gansu later that year, where he proudly received diplomatic envoys from a number of countries.
More than 1,400 years after the emperor's personal tragedy here, we were lucky enough to be welcomed more benignly by the deep valley and towering rock faces.
As we drove toward the interior of the mountain, a very different natural landscape appears - grassland. As it was autumn, the grass had taken a warm golden hue.
Gold was everywhere, covering the mountains and the valleys like a huge soft blanket. The sight of the vast grassland was so breathtaking that everyone in our minibus fell silent. We are so small, our minibus so small; that was the feeling that hit us.
Then we noticed small white spots, moving amid the great expanse - sheep. They wandered the peaceful grassland, part of the age-old rhythms of the land.
At that moment, we began to understand why the emperors and the khans of different tribes fought for thousands of years for this area.
During the Han Dynasty (202 BC-AD 220), the Xiongnu people lived in the Qilian area in today's Gansu Province. However, during the war between the Han and Xiongnu in 121 BC, General Huo Qubing expelled the Xiongnu from the mountains and their khan surrendered to the Han Emperor Wu.
Capturing the Qilian Mountains had great significance for Han Dynasty: it meant they finally had lush grasslands, ideal for breeding warhorses; and the rich Hexi Corridor area was now safe for agriculture and commerce. The Silk Road began to prosper.
But for the Xiongnu, it was a devastating loss. "Qilian" means "sky" in their language and according to Xiongnu poetry, the loss of the Sky Mountains was so traumatic to their way of life that it left their cattle unable to reproduce.
From then on, the area witnessed more than 1,000 years of wars between the Han and tribes such as the Xianbei, the Qiang and the Mongols.
Previously, this chronology had just seemed dry facts from history textbooks. But as we stood on the mountains themselves, all these stories came to life.
It had been difficult for us to understand why a mountain range was so important except for its strategic location along the Silk Road and why after losing it, the Xiongnu people lost their power in west China.
But as we drove deeper into the center of the Qilian Mountains, the answer became clear. The importance was because of the rich resources of the Qilian Mountains, perfect for nomadic tribes.
They offer abundant grass for livestock and water from the melting snow on the peaks. The sheltered valleys provide ideal sites for erecting yurts. It was a paradise hidden in the mountains, far from the outside empire.
Snowmelt from Qilian also provides water for the whole Hexi Corridor area, making it one of the richest commercial areas in history, despite its harsh natural environment.
The Xiongnu people are long gone and the Qilian Mountains have been at peace for many years. But present-day inhabitants still follow an old lifestyle. Flocks of sheep and herds of horses graze peacefully, some straying on to the highway and in no hurry to move out of the way of vehicles.
Every now and then, a small creek came into view, the clear water sparkling in the late afternoon sunshine.
What has changed is that the shepherds now often favor motorcycles over horses for work and that brick houses have replaced yurts.
Most of the mountain people are Tibetan. Their prayer flags add vibrant color to this peaceful meadow that has beguiled us, as no doubt it beguiled the Han emperors more than two thousand years ago.
Later we learn that the best time to visit the Qilian Mountains is in spring, when the grass is at its greenest and the meadows filled with drifts of flowers.
And as the mountains are slightly remote from big cities, and not on tourist trails, they are still a hidden paradise for travelers along this age-old route.
If you go
How to get there:
You can fly to Lanzhou, the capital city of Gansu Province first. There are direct flights connect Lanzhou and other big cities such as Beijing and Shanghai. Then take a train from Lanzhou to Zhangye City. Dozens leave from Lanzhou Railway Station to Zhangye every day on a journey that takes between five and seven hours.
Highway G227 starts at Zhangye City in Gansu and runs south through the Qilian Mountains, then goes to Qilian County and Xining City in Qinghai. It is regarded as one of the most beautiful highways in China.
Driving through Qilian Mountains takes four to five hours. If you follow the G227 highway, you can reach Xining, which is about 300km in the southeast.
Where to stay:
Qilian County in Qinghai Province is right at the foot of Qilian Mountains. The neat-looking little county has plenty of home-style hotels.