When reading the brisk, dynamic, and detailed portrayal of events in the Gospel of Mark, one understandably might overlook phrases such as "into the borders of Tyre and Sidon" (7:24), or "unto the sea of Galilee, through the midst of the coasts of Decapolis" (7:31). However, by pausing to investigate this geography, the reader can gain deeper insights into the record of Jesus' travels. Possibly the author of this Gospel planted such landmarks for a purpose. Often geographical notations can help verify a narrative and thereby enlarge its message.
I've taken a look at several such passages in Mark's Gospel in the context of an overarching theme: the physical and emotional pressure exerted on Jesus and his disciples in opposition to the divine power of his mission.
In the Gospel of Mark, Jesus emerges in public at the height of the stir caused by the reform ministry of his cousin John. Hordes of Jews are converging outside Israel proper for wilderness baptism "in Jordan," as though preparing to enter the promised land anew. Jesus' mission begins soon after his own baptism by John, and Jesus soon finds himself a magnet for other crowds.