Cool satellite view of dozens of oxbow lakes formed when a river changed course
Today's maps found on the interwebs. 
When a river changes course on its flood plain, it can leave an entire bend of the river cut off from the new flow, forming an oxbow lake. Seen in bright blue in this shot of the Songhua River in northeast China, they are usually narrow crescents.
Found at https://boingboing.net/2018/06/26/cool-satellite-view-of-dozens.html
