a wanderer above the sea of fog
Wanderer above the Sea of Fog (German: Der Wanderer über dem Nebelmeer), also known as Wanderer above the Mist or Mountaineer in a Misty Landscape,  is an oil painting c. 1818  by the German Romantic artist Caspar David Friedrich. It has been considered one of the masterpieces of Romanticism and one of its most representative works. It currently resides in the Kunsthalle Hamburg in Hamburg, Germany.
Robert Macfarlane discusses the painting in terms of its significant influence on how mountain climbing has been viewed in the Western world since the Romantic era, calling it the “archetypical image of the mountain-climbing visionary”, and describing its power in representing the concept that standing on mountain tops is something to be admired, an idea which barely existed in earlier centuries. 
Media related to Der Wanderer über dem Nebelmeer at Wikimedia Commons
The painting is composed of various elements from the Elbe Sandstone Mountains in Saxony and Bohemia, sketched in the field but in accordance with his usual practice, rearranged by Friedrich himself in the studio for the painting. In the background to the right is the Zirkelstein. The mountain in the background to the left could be either the Rosenberg or the Kaltenberg. The group of rocks in front of it represent the Gamrig near Rathen. The rocks on which the traveler stands are a group on the Kaiserkrone. 
One can’t look at the painting without instinctively putting yourself in the man’s shoes and imagining how small he must feel before such a vast and immense display of environment. However, the man stands with confidence before all this, almost as if he has no regard for the hazard around him. This juxtaposition shows how small mankind is on a cosmic scale, while paying homage to man’s defiant instincts and tendency to try to shape the world for his own anyways.
The painting is particularly gray, with little variation, giving it a somber, almost ominous atmosphere. The rocks, mountains, and fog are gray, and while the water is a deep blue, the splashing of waves is grayish white, further adding to the grayness. The sky is cloudy, so it too is gray. The man is wearing black pants and a black coat with a white shirt collar exposed, and has blonde hair. I think the extensive use of gray is meant to give ambiguity to the scene and over-exaggerate the fogginess of the area.
Like so many of paintings by the German Romantic painter Caspar David Friedrich, the images focuses on a person gazing out over nature. We gaze out alongside him, a few paces behind perhaps, but still a companion in the moment. The terms for this device is Rückenfigur, or figure seen from behind, a compositional device by which the viewer can more readily identify with the scene.
A man stands on top of a crag of rocks, overlooking a valley cloaked in mountain mist. Other ridges rise through the fog, giving the impression of islands in a sea.
Use of technique:
Once again Friedrich employs the Ruckenfugen technique in which he paints the figure with his back towards the viewer. This makes the figure something of a mystery to the viewer – they are unsure what he is thinking or his reaction to the landscape that they too are taking in.
Friedrich chose to paint this landscape vertically instead of the much seen horizontal orientation. The upright position of the canvas models the uprightness of the figure in the painting.