When Xi Jinping was a child he lived in a yaodong for a time. What is a yaodong?

A yaodong is a form of earth shelter.

These dwellings are common in China's Loess Plateau in the north of the country. They are carved out of hillsides or may be the result of horizontal excavations. The earth around the dwelling acts as an effective insulator, both in winter and in summer.

Yaodongs have been used for many centuries. In 2006, it was estimated that as many as 40 million people lived in them.

https://en.wikipedia.org/wiki/Yaodong