At first, I almost stepped on it, so inconspicuously it lay on the hiking trail, but as I stop and adjust the camera, it turns and retreats - a common European adder?; 21.09.2007

It's a pity that the image description unfortunately does not indicate in which country and region of the world this photo was taken.

Country: Czech Republic; Region: Ore Mountains, red-marked hiking trail between Cinovec (Bohemian Cinnwald) and Komari hurka (Mosquito Tower).

Yes, you are right: it was definitely good to quickly change my stride and not step on it. Most likely, otherwise there would have been significant difficulties in communication when I tried to assure that it happened by accident - ch-ch-ch-ch...
Honestly, it only became really clear to me at home when looking at the picture what kind of encounter I had; it was really gone quickly. - Regards, Volkmar