Photo taken on Feb. 3, 2018 shows underground courtyards in Shanzhou District of Sanmenxia, central China's Henan Province. Underground courtyard in Shanzhou, unique residence in mountainous areas of western Henan, is listed as the national intangible cultural heritage in 2011.Photo:Xinhua

Photo taken on Feb. 3, 2018 shows underground courtyards in Shanzhou District of Sanmenxia, central China's Henan Province. Underground courtyard in Shanzhou, unique residence in mountainous areas of western Henan, is listed as the national intangible cultural heritage in 2011. Photo:Xinhua

Photo taken on Feb. 3, 2018 shows a lantern-decorated underground courtyard in Shanzhou District of Sanmenxia, central China's Henan Province. Underground courtyard in Shanzhou, unique residence in mountainous areas of western Henan, is listed as the national intangible cultural heritage in 2011. Photo:Xinhua

Photo taken on Feb. 3, 2018 shows a lantern-decorated underground courtyard in Shanzhou District of Sanmenxia, central China's Henan Province. Underground courtyard in Shanzhou, unique residence in mountainous areas of western Henan, is listed as the national intangible cultural heritage in 2011. Photo:Xinhua

Photo taken on Feb. 3, 2018 shows the lantern-decorated underground courtyards in Shanzhou District of Sanmenxia, central China's Henan Province. Underground courtyard in Shanzhou, unique residence in mountainous areas of western Henan, is listed as the national intangible cultural heritage in 2011. Photo:Xinhua