OLDEST - Observatory in East Asia, Cheomseongdae - Gyeongju, Korea
Posted by: 
silverquill
N 35° 50.076 E 129° 13.138
52S E 519776 N 3965625
Cheomseongdae is the oldest astronomical observatory in East Asia, and Korean National Treasure # 31, located in the city of Gyeongju, ancient capital of the Silla Kingdom which reigned for nearly 1,000 years.
Waymark Code: WM6BDC
Location: South Korea
Date Posted: 05/07/2009
Views: 12
Designer: Kim Yung-choo
Image Area: 20mm×24mm
Perforation: 11½
Sheet Composition: 10×10
Paper: White Japanese paper; Wave-line watermark
Printer: Korea Books Printing Co., Ltd., Seoul
From the Wikipedia:
Cheomseongdae
Cheomseongdae is an astronomical observatory in Gyeongju, South Korea. Cheomseongdae means star-gazing tower in Korean. Cheomseongdae is the oldest surviving observatories in East Asia, and one of the oldest scientific installations on Earth. It dates to the 7th century to the time of kingdom of Silla, which had its capital in Gyeongju. Cheomseongdae was designated as the country's 31st national treasure on December 20, 1962.
According to Samguk Yusa, Cheomseongdae was constructed under the reign of Queen Seondeok (632-647) near the capital of the kingdom. Cheomseongdae means "star gazing platform". The tower is built out of 362 pieces of cut granite which some claim represent the 362 days of the lunar year. Some surveys of the site have indicated that there are 366 blocks. It has 27 circular layers of stones (some associate it with the fact that Queen Seondeok was considered to be the 27th ruler of Silla) surmounted by a square structure. 12 of the layers are below the window level and 12 are above. There are 12 large base stones set in a square, with three stones on each side. These sets of 12 may symbolize the months of the year.
The tower is 5.7 meters wide at the base and 9.4 meters tall, and filled with earth up to the level of the window. Its construction style parallels that used at the Bunhwangsa Temple in Gyeongju.
The Cheomseongdae is the oldest surviving observatories in East Asia, though some claim that Cheomseongdae was not suitable for astronomical observation. Others posit that it was used for astrology rather than astronomy, though during that era there was little differentiation between the two. Some scholars have argued that the Cheomsongdae's design was heavily influenced by Buddhism, noting similarities between its design and Mount Sumeru, the center of the world according to Buddhist mythology.
Cheomseongdae was built during the reign of the Silla Queen Seondeok (r. 632-647), and is the oldest astronomical observatory in East Asia. The observatory is 5.17 meters in diameter and 9.4 meters in height. The bottle-shaped tower mad of square granite stones stands on the square stone base. The length of the stone base is 5.35 meters. Up to the 12th layer from the bottom, this hollow tower was filled with soil and pebbles. Between the 13th and the 15th layer, there is a square opening through which an observer can ascend to the top. Cheomseongdae gives a sense of balance, harmonizing straight lines with curves.