Cheomseongdae
Though perhaps a bit underwhelming at first, this 9-m-high (30 feet) stone tower takes on more weight when you consider its historical context. Constructed in the 7th century, it's Asia's oldest surviving astronomical observatory, making it one of Korea's great scientific contributions to the world. It's worth a visit just to see the obvious pride the town takes in this marvel. Notice the numerical symbolism: the tower's 362 granite blocks are said to represent each day of the lunar year.
