New landform - something that looks like rivers. I call them pseudo rivers. Of course this is not a real rivers, i.e. they don't flow from highland to the sea, they have no inflows etc. River nets sometimes look strange - like blood vessels, and even can make loops. To have 3D water, their surface must be on the sea level, so they really look good only near shores. So I simply limit their generation on highlands. However, they sometimes create a nice looking valleys in mountain ranges.