The surface of the Sun - The chromosphere
The chromosphere lies just outside the photosphere, and is almost completely transparant. On the picture to the left, taken during a solar eclipse, the chromosphere can be seen as a red glow just around the Sun. (Click on the image for a larger version.)
If you look closely, you'll also see solar flares in the chromosphere. On the picture to the right you can see a very large example. Click on the image to find out more about solar flares.
The temperature in the chromosphere rises slowly as you go further out; from about 4300 degrees to 8300 degrees at the edge. At that point, the temperature rises sharply.