The Camino backpack is one of the most essential pieces of gear that you will need because it will house all of your items for the entire walk. You need a backpack that is large enough to carry all of your gear and is designed to limit the weight on your shoulders. Below is a list of backpacks that I have seen along the hike and some that are recommended by friends who have done the hike before. A 50L backpack should be sufficient for carrying all of your equipment without being too heavy itself.