Ruins at the Jiaohe Ancient City, a local capital until Genghis Khan besieged and destroyed it in the 13th century.

Jiaohe was divided into four sections. In this photo are the remains of where the soldiers were housed.

Another section of Jiaohe was set aside for religious use. The walls here are what's left of a Buddhist temple.

Hikers walking back from a visit to the Stupa Forest part of the religious precinct. There's a big stupa in the middle, surrounded by four groups of 25.

A group shot in the Flaming Mountains, not far from the Bezeklik Grottoes.

Full moon over our desert campsite. It was really, really windy during the night, and we'd collected a lot of rocks to hold down our tents.

We woke up to clear skies for sunrise the next day.

Sunrise in the desert.

The group poses with all the rocks we'd collected to hold down the tents.

After waking up in the desert and having breakfast, we headed off for a hike. In this shot, we can see a long mountain range behind the campsite.

The desert in this area was rocky, but there were also some interestingly coloured dirt hills to climb up on.

A view of the hills near our campsite.

On the way to Dunhuang we stopped for a picnic lunch, and took the opportunity to stretch our legs with a walk in the stony hills.

Hikers in the hills.

We returned to the jeeps, where the drivers were cooking for us.

Just before arriving in Dunhuang, we stopped to take a hike over to some Han Dynasty Great Wall. The Han Dynasty built walls from rammed earth, and some still remains out there in the desert.

We took a group photo under a big section of old Han Dynasty wall.

The wall has been eroded by almost 2,000 years of wind and rain.

Irrigation canals have also eroded some of the wall here.

The wall stretches out into the desert.

This section has been flooded by irrigation.

In Dunhuang, we took a hike in the desert, heading for Crescent Lake.

The sand dunes on this side are mostly free of people.

We stopped for a group photo before climbing a big sand dune.

From the top of the dunes we could see Crescent Lake.

The green area is the outskirts of Dunhuang City, and the desert is getting closer and closer.

We took the back way to Crescent Lake and avoided the touristy side. In this photo, you can see what was waiting for us on the tourist side!

The temple at Crescent Lake.

After Dunhuang, we drove on to Jiayuguan, passing old signal towers in the desert.

In Jiayuguan, we visited the Jiayuguan Fortress, the westernmost fortification of the Ming Dynasty.

The fortress has been restored, and is in very good condition – a good chance to see what things would have looked like when it was built in the 15th century.

One of the big towers above the gates of the fortress.

Looking west from the eastern wall of the fortress.

Another of the big towers.

This wall stretches south, towards the Qilian Mountains. The fortress is sited in the 8km gap between the Qilian Mountains and the Black Mountains – an ideal way to keep an eye on people coming east along the Silk Road

One of our hikers took a microlight flight above the fortress.

To the north of the Jiayuguan Fortress are the Black Mountains. We visited a stretch of wall that dates back to the Han Dynasty. The wall here was repaired using Han Dynasty techniques.

More of the wall in the Black Mountains.

We climbed up to a lookout tower, and could see the Jiayuguan Fortress in the distance.

A view from the top.

One last photo – the hiking group, and our very friendly and professional drivers.