The geography in Europe had a huge impact on the lives of the citizens in the Middle Ages. Those who lived by the mountains were in a good place for protection and shelter, but it was just as hard for them to escape the mountains as it was for invaders to attack. Also, life in the mountains wasn't a very popular trade site. On the contrary, living by the sea or rivers had great advantages for trade with places near and far. Living in forests had advantages with animal availability for food and living in an open space meant vulnerability but it was easier to be in contact with other groups. The geography in the Middle Ages had its ups and downs, as it does with many areas of land, but it all contributes to what we know about the Middle Ages today.
Political map of Europe, 600 AD:
Physical map of Europe, circa 650 AD: