The "pit yards" in Sanmenxia of Henan Province, dubbed as the "architectural miracles" in China or "underground Siheyuan (traditional single-story houses with rooms around the four sides of a courtyard)" in north China have received effective protection. Local Cultural Relic Department has established protection layouts and decided protection areas for the underground courtyards. The yards are also listed as the Cultural Relic Protection unit of Henan Province.

The "underground Siheyuan" is also called patio yard. It originated from the troglodytism of ancient human beings, with a history of about 4,000 years. With the development of time, the underground Siheyuan for "troglodytism" are well preserved only in Sanmenxia of Henan Province nowadays. There are still more than 100 underground villages and about 10,000 patio yards in the city. They still keep the wonderful vision of underground village "seeing no houses while entering the village, spotting no one while hearing their voices."

By People's Daily Online