Millennia-old house with temperature adjusting designs found in Inner Mongolia

Archaeologists have found a stone house with "temperature adjustment" designs dating back to the early bronze age in North China's Inner Mongolia autonomous region.

The ancient dwelling at the Xiaotangshan ruins site features archaeological designs that helped it stay cool in summer and warm in winter, said Inner Mongolia's institute of cultural relics and archaeology.

The house is comprised of three circular stone walls, each about one meter apart and with partition walls in between to direct drafts of air. The innermost circle was built about one meter underground, which also helped regulate the internal temperature, said Lian Jilin, a researcher with the institute.

Such an ancient architectural design is the first of its kind ever discovered in China, said Lian, who described it as an "air-conditioned house."

Xiaotangshan ruins site is part of the Lower Xiajiadian Culture, a branch of the northern bronze culture dating 3,500 to 4,000 years ago to the Xia and Shang dynasties. Experts believe that this bronze-age site boasted advanced metal smelting technology.