How do I access new areas like the Military Bunker or The Last Shelter?

Some areas in the game need to be unlocked with certain items. For example, the Military Bunker will require you to have a specific item in order to go there.

Checking Plane Crashes, or other events drop crates that can have the item you need. The Military Bunker will require you to have a "Sector Pass A" to go in. These items drop at random so try to check these areas often. Other Sector Passes will unlock other areas so check the message that will appear once you have them.

Other areas on the other hand that are far will require you to have a vehicle. The Last Shelter is very far, and you need a transport vehicle to get there. You can make these using your blue prints. Once you have better transport vehicles, you'll also be able to go to more places.