Aerial photograph of the Fallenbacher Turm, or Fallenbacher Tower (dark grey rock in the foreground, 2704 metres altitude), and its surrounding mountain in the Lechtal Alps, Austria. This dark grey limestone formation is located on red layers of a very hard chert containing limestone. At back left: Holzgauer Wetterspitze (2895 metres) and back right: Fallenbacher valley.