"Then he returned from the region of Tyre and went through Sidon to the Sea of Galilee, in the region of the Decapolis."To get an idea of where Jesus went here is a map of a possible route:
As it is the route of Tyre to Sidon does not seem to be the most direct route for Jesus to take. In fact it would probably be 15 to 20 miles out of the way. So, it looks like Mark made an obvious blunder on geography, and therefore didn't know Palestinian geography and hence the author of Mark probably wasn't John Mark who lived in Palestine and knew Peter, right? Wrong.
Its All About Elevation
As you can see from this second relief map I have drawn two possible paths. The one in red would have taken Jesus through a very mountainous area, you can see how mountainous the area is by googling Mount Meron and looking at the images. Going north to Sidon and then over and down would have taken him and the disciples through a pass and would have a avoided most mountainous regions. Add to this a comment from Tim Mcgrew that there was a pass from Sidon down to Galilee that stayed close to water, and it makes perfect sense. Mcgrew said this,
“There is a pass from Sidon through the mountains to the Jordan river valley, where foot travelers to Galilee could have fresh water for the journey.”
Instead of showing an ignorance of Palestinian geography it would show a detailed knowledge of the geography of the region.
So, it would appear that another supposed problem with the gospels isn't a problem at all. Rather, what we have is firsthand knowledge of first century Palestine that we would expect from someone who lived there. This knowledge fits with John Mark who was with Peter, and wrote down his "memoirs" as early tradition said. In fact, this whole issue of geography may not be a problem at all. It could have been the case that Jesus had some business in Sidon that Mark decides not to tell us. However, the details I have given makes me think Jesus was trying to take the least mountainous route.