I'm looking for a novel that was probably published between 1990-1996 and it was about alien contact with ancient civilizations. I don't remember much from the book but I do recall the protagonists visiting temples and pyramids in south america. I believe there was even an alien contact in the book or at the very end.
Details are sparse, I know... It's one of the books I read when I was young and I checked it out from the library. That was almost 20 years ago and I've moved across the country since then, but I really want to read the book again.
Thanks all for reading!