800AD?
"Kuelap’s mystery has barely been studied. Construction began about 800AD at the same time that the Andes’ most spectacular empire began its expansion from Bolivia. This was the Tiahuanaco or Wari Empire, known as “The Golden City Building Era of the Andes”, or the Middle Horizon."
Who are these people and why do we know so little about them? (Get a large grant and go find out for us, lol)