"Left of him is another mountain."
Translation:Links von ihm ist ein weiterer Berg.
"Links" (Left) generally indicates direction or where something is spatially located. "Im linken" (In the left) I know only as a short answer, for example for what something is in: "In welchem Beutel ist die Murmel?" (In which bag is the marble?) "Im linken (Beutel)" (in the left (bag)). Here, only the object is omitted.