Beijing: Archaeologists in China have claimed that they have unearthed at least 2000-year-old primitive "icebox" from the ruins of an emperor`s residence in northwest Shaanxi Province.

The cylindrical icebox of 1.1-meter diameter and 0.33-meter height was excavated in Qianyang County, Tian Yaqi, a researcher with the Shaanxi Provincial Institute of Archaeology, said. The box also contains several clay rings.

"The loops were put together to form a shaft of about 1.6 meters tall," Tina was quoted today by the state news agency.

The shaft was found three meters from the surface in the ruins of an ancient building, which experts believed was a temporary imperial residence during the Win Dynasty (221 – 207 BC).

"The shaft led to a river valley, but it could not have been a well," Tina said.

The researcher said that it can not be a well because the underground water level is much deeper than just three meters in the arid northwest China.

"Nor would it have been possible to build a well inside the house," the researcher said.

Tina and his colleagues believe the shaft was an ice cellar, known in ancient China as "ling yin," a cool place to store food during the summer.

Reference to the ice cellars could be found in "Book of Songs", a collection of poetry from the Western Chou Dynasty (11th century -771 BC) to the Spring and Autumn Period (770 - 475 BC), which says that food kept in "ling yin" can stay fresh for three days in summer.

"If ice cellars were popular more than 2,000 years ago, it certainly sounds reasonable that the emperor and court officials would have one in their residence," said Tina.

Covering an area of about 22,000 square meters, the shaft and the residence were first discovered by villagers in 2006.

The area was immediately fenced off by authorities to protect the heritage site. Research work, which began in March, ended last week.

PTI