There are a wide of very good reasons that maps are important to us in everyday modern society. Knowing exactly where we are intending to go and how to get there is, of course, the primary reason.
However, when one thinks back to the age of exploration of the world when little to nothing was truly known about the geography of the world, then the maps made by previous explorers became not only good tools but essential tools to continue that exploration by those who came after and wanted to go to even further than previous adventure seekers.
Layout of Main Routes
Understanding the main routes of travel and the possibilities of hidden dangers along the way was of paramount importance to world travellers back in the middle ages.
Knowing what lay ahead of you and what you may possibly face in the way of impediments was crucial for early explorers. Just knowing that a way had been trail blazed before you, limited your exposure to uncertain elements that could potentially cause your party peril.
Not knowing that the route you had chosen to take included forbidding mountains could mean that the expedition would falter at that point if the required supplies were not included in the stores that you had brought along with you to traverse those peaks.
To Source Out Supplies
The ability to read a map and locate sources of supplies such as water and even potential food sources was also crucial to the success of many expeditions during the search for new lands across the ocean by those who followed in the footsteps of the great explorers such as Columbus and even Lewis and Clark.
Even a rudimentary map could be helpful in certain situations. Knowing how to navigate using information supplied to you from others could assist in making sure that you were heading in the proper direction.