It's not a tourist area, it is cheap to rent a car with a driver in the Gobi (2 days, 500km, 6 people) AUD$220, accommodation in the Ger AUD$2.70, lunch AUD$2, 1 hour camel ride AUD$3.50. I had good memory about this country except food, it's not my favourite. It's cold, so we went directly south.
In China we visited Handing Monastery and Yungan Caves close to Datong, Forbidden City, Summer Palace, Army of Terracotta Warriors and many more religious, ancient culture and architectural attractions. That was something new and really interesting, but I'm not into arts and saw only a few of them. I recommend hire a bike in Beijing. Riding in the streets is an exciting experience. There are no traffic rules: red light is just a suggestion to stop, one way road can mean two or even three way road. Bigger or faster has the right of the way. You need eyes in the back of your head, noisy hooters, good brakes and fast reflexes, that how you survive.
The Great Wall of China is an impressive attraction. You can go to new renovated parts of the wall (look for the crowd) but I've chosen to go to Huang Hua Cheng, the non-commercial tourist region. Many parts of the wall are destroyed and overgrown by bushes, which makes it more real. I walked up the mountains for more than 3 hours. Almost vertical, the wall required climbing very often. I decided to spend a night under the stars. That wasn't a warm idea (8°C below zero) but sunrise in this majestic scenery gave me a sense of satisfaction. Moreover I didn't meet any tourists.
Just after crossing the Tropic of Cancer, we could throw away our winter clothes. In the Stone Forest, close to Kunming, we entered into tropical scenery. I often travelled by night and during day I explored. Between smaller towns you couldn't sleep on the train, too noisy and crowd. These distances were similar to distance between Sydney and Melbourne. Trains between major cities were nice, clean and comfortable with soft seats, even they were the cheapest and called hard seat. If I didn't have Mandarin language book you could forget about proper communicating here. English was useful only in popular tourist places. Buying food was lot of fun but it was better not to know what I had just eaten. It was very cheap there, for example a large bottle of beer cost me only AUD$0.40