Gord's Colombian mud volcano was fairly easy to solve due to clues which had nothing whatsoever to do with the actual mud volcano! I like that kind of puzzle where a whole lot of different and seemingly unrelated clues come together and point out a very limited area to search in.
For the next one, I considered for a moment asking for the southernmost known eclogite in teh Western Greiss Region of Norway. But since that is a small lens (about 20x80cm) in a shear zone, exposed under an overhang in my own garden, I decided that it was a bit TOO impossible. :)
Instead, I give you hydrology.
This one shouldn't be too hard, I think - but I liked the pattern it makes.
As always, post a comment with latitude and longitude and write something about the (geologic/geographic/hydrographic) feature in the picture. If you win, you get to host the next one.
Previous WoGEs are collected by Felix on his blog and a KML file.