I wonder if they're kilns or furnaces rather than non-functional monuments, give...

jewel · on Feb 28, 2016

I would expect the interior to still be blackened. Here is the photo from the article closer up:

https://maptia.imgix.net/photos/75985/1456101557.jpg?cs=srgb...

From what I gather from other articles, no human remains have ever been extracted from them. Perhaps the buildings were used for a religious purpose or for temporary shelter.