"Heritage Sites of Astronomy and Archaeoastronomy in the Context of the World Heritage Convention" (also available here) is a collaborative study by the IAU Working Group on Astronomy and World Heritage and the International Council on Monuments and Sites (ICOMOS). The study has been endorsed by the UNESCO World Heritage Committee, at its 34th session in Brasília, Brazil, marking the first time a study in scientific heritage has been so endorsed. [more inside]
The Thirteen Towers of Chankillo in Peru may be the Western Hemisphere's oldest known full-service solar observatory, showing evidence of early, sophisticated Sun cults, according to archaeoastronomy professor Clive Ruggles. The 2,300-year-old complex featured 13 towers running north to south along a ridge and spread across 980 feet to form a toothed horizon that spans the solar arc. Last year, another ancient observatory was discovered in Peru by Robert Benfer. The Temple of the Fox is 4,200 years old, making it 1,900 years older than the Chankillo site, but wasn't a complete calendar.