Hi; I really don't know, but you may find at least some interesting leads about ancient astronomy sun-studies at http://solar-center.stanford.edu/AO/.

Hi Kristin,

It's hard to say how many sites around the world may have been used as solar observatories. There are some really famous sites that have solar connections, such as Stonehenge in England and Chichen Itza in Mexico. But there are many ancient sites that have not yet been studied for possible solar significance. That's what makes archaeoastronomy such an exciting field - there is still so much more to discover!

-Nancy