Imaged by Claudia Hinz from the 1848m high Wendelstein Observatory in the Bavarian Alps, Germany. ©Claudia Hinz , shown with permission.
The tip of the blue triangular shadow of the Wendelstein marks the antisolar point directly opposite the sun. The antisolar point is also the centre of rainbow here seen unusually arcing downwards. If there are enough raindrops in the right places, rainbows can be complete circles as can sometimes be seen from mountain slopes or - if you are prepared to get wet - within the spray of a lawn sprinkler.
Daily Wendelstein Picture Claudia Hinz, Atmospheric Optics Wendelstein Observatory