So anyone who remembers the five minutes in the movie that take place outside Minas Morgul (the evil, green, glowy tower where Sam, Frodo and Gollum watch all the black riders and soldiers march out) will have some vague idea of what this is a picture of.
The tower was originally called Minas Ithil (meaning, "Tower of the Moon") and was a way of watching over Sauron as he hid in Mordor. Eventually, in the year 3429, he takes over Minas Ithil, burns the White Tree there, and turns it into Minas Morgul ("Tower of Black Sorcery").
I've always wanted to do a Minas Tirith or a Weathertop. For some reason, those two have always captivated me. And I doodled this one without really aiming for either, but upon image searching the various Middle Earth structures I found that Ithil most closely resembled this design, so there it is. I just wish I'd used a white stone on top.
One thing that always fascinated me about Minas Morgul/Ithil is what happens to it after the film. It may very well say in one of the appendices I haven't read. But, you know, we get to see what becomes of the rest of Mordor, but not the Morgul Vale. Why not?
Perhaps it's because, like Orthanc, Minas Morgul used to be a source of goodness in the world. So, maybe there's no reason to destroy it. Maybe they just went back there, cleaned out all the ghoulies, re-erected the tower and made it into a real place again. Who knows?