Littlestone wrote:
Fascinating stuff David! Does your research suggest that (astronomical) observations were made principally from inside or from outside of the structure (or perhaps equally from both?).
Good textbook on early Asian astronomy .From a different time (7th century) and a different place (South Korea) there are the stone tower observatories – Cheomseongdae perhaps being the most famous. More here –http://www.newworldencyclopedia.org/entry/Cheomseongdae (Cheomseongdae means ‘Nearer the Stars Palace’ :-)
Xu Zhentao, David Pankenier, and Jiang Yaotiao. East Asian Archaeoastronomy:
Historical Records of Astronomical Observations of China, Japan and Korea.
Amsterdam: Gordon and Breach, 2000.
