March 2019, on the way with a school class in the Harz Mountains, Germany. On our way to the Titan RS, the longest suspension bridge in Europe, we came to this tunnel. In summer a lot of motorcyclists drive through it, because it sounds so loud. I like this picture because of its symmetry and depth. It looks as if the spaceship Enterprsse is going to warp speed.

This photo was not posted on Unsplash.