The Arch of Triumph is my name for it since I don't know what the official name is. Not to be confused with the Arc de Triomphe in Paris which took only about 30 years to build where as this one has been under construction for a couple million years and is still a work in progress. I call it the Arch of Triumph because I had to make a pretty good climb fairly quickly to get this angle while the sun was still illuminating the inside of the arch.
This is an HDR image and if you scroll your mouse over the image you should see the best of the 9 images used to create the one you see. When you mouse over you will see the second image make a small size jump, that is simply because I did not bother putting a frame around it. Which do you like better?
Note: Thanks to Dave for the tutorial on how to do the "mouse over" trick.