While most areas will be accessible via the rail transport system or by sea using a boat, some zones won't be directly connected to the hideout and will require passage through the Maintenance Tunnels to reach them.
These tunnels will sometimes be lit by emergency lights, while at other times they may be completely shrouded in darkness.
Additionally, since the areas reached through the maintenance tunnels are more remote, they won't have extraction zones. To return to the hideout, you'll need to go back through the tunnels.
