I went to Guilin during my honeymoon. It's very much chocolate box rural China, so was lovely to see it (briefly) and other places with similar characteristics.
We also went to Nepal and India so I'm hoping more familiar places come up on the series.
We started in Hong Kong, worked our way north to Beijing, into Mongolia, back to Beijing and were really lucky with timings to get permits to Tibet and travelled through Tibet to the Nepalese border. Through Nepal, aross the north of India to Rajasthan, then flew south and travelled across the south of India.
I joked to DH that if we were still married by the time we got home from honeymoon, it was going to be a good marriage. Still going well 15+ years later 
Race Across the World always makes me nostalgic. I'd love to have another go at that spontaneous style of travelling again.
Our arrangements in advance were flights in, flights out, 3 visas and the first hotel. The rest we made up on the go. The beauty of not having plans was being able to follow obscure recommendations as we went and being able to dodge events such as the 60th anniversary of the Chinese Revolution that have a major impact on travel.and accommodation arrangements.
The first really different thing that struck me before we even got to the hotel was the bamboo scaffolding!