The Banaue Rice Terraces was built 2000 years ago (?) by the indigenous people of Ifugao mostly by hand. Covering an extensive area of over 10,300 square kilometers, it is a massive engineering wonder. According to the old Philippine Tourism website, when these terraces are all connected in a straight line, it would encircle half the globe!
Aside from the great effort needed to build such a colossal structure, what makes these terraces truly breathtaking is that it reflects the culture of the people who have lived in these mountains for millennia.