Hi everybody, while using Google Earth I came about a few interesting structures in the middle of nowhere on the border between Bolivia and Brazil. I have posted this in the offical Google Earth forums as well, but it seems nobody has an idea what these might be. The structures are definitly man-made and haven't been in use for quite some years and are overgrown with gras and trees. Diameters range from 80 to 160m and the trenches are aprox. 2-3 meter deep and up to 10 meters wide I think. If you use Google Earth you can download the kml-file here: http://bbs.keyhole.com/ubb/showthreaded.php?Cat=0&Board=EarthHistory&Number=687765 There is also the possibility to use Google Maps in your browser - in case you don't have Google Earth installed. And just to attract some attention without having to click on a link: This ist what these forts/structures/whatever look like. Has anybody any idea what they are? Many thanks for all ideas. Greetings spinnne