I won't go into an explanation of what raised fields are; other folks have studied them longer and taken much more time to understand them than I have. I'll just put in this link.
I was, however, lucky enough to see them in person recently and was pretty blown away. Not just by the raised fields, but by the landscape in general. So windswept and intense. And the people were absolutely incredible. There is still some truly amazing innovation going on at the household level in this part of the world, as I expect there is everywhere else as well. It was a joy to see. Hope you like the pics.