Passage: The gospel, however, appears to rely on several underlying sources, which vary in form and in theology, and which tell against the story that the gospel was based on Peter's preaching.Most scholars believe that Mark was written by a second-generation Christian, around or shortly after the fall of Jerusalem and the destruction of the Second Temple in year 70.Richard Bauckham has noted that the geography in Mark is accurate when looked at from the perspective of fisherman from Capernaum, which is consistent with Mark relaying the gospel from Peter, who indeed was a fisherman. Many scholars use modern maps to gauge Mark, which often results in errors in judging Mark's geography. A fisherman would not have had a modern map in mind, but instead a mental map based on his experiential world.According to some, Mark's geography was not always accurate, for example Mark 7:31, describing Jesus going from Tyre to the Sea of Galilee by way of Sidon (20 miles farther north and on the Mediterranean coast). The author of Mark did not seem to know that one would not go through Sidon to go from Tyre to the Sea of Galilee, and there was no road from Sidon to the Sea of Galilee in the 1st century, only one from Tyre. Catholic scholars have interpreted this passage as non-problematic since Jesus would have traveled in a wide circle, first north, then east and south.

Question: Why does gaugign Mark's geography often result in errors?
scholars use modern maps