This is highly debatable and open to hundreds of interpretations. It could be a sign that your secret hideout/passageway is going to be discovered or that you need to make a secret hideout/passageway.
They could have secret passageways leading out.
A locked safe in a dream usually represents a secret. Unlocking the safe would represent discovering the secret.
Unknown
If by passageways, you mean the bronchi and bronchioles, they're there as a tunnel to supply oxygen from the outside to the lungs.
They are buddy portals that u click in ur house that teleport you to the house you picked.
dream
Nothing Really, A dream is something you Think about or worried about, Perhaps Your Worried about Someone evil, Maybe your Friends Are hiding a secret!!!
The Secret Dream-lives of Engineers - book - was created in 2006.
It is because the house was a stop in the moving of slaves. The passageways helped keep the slaves safe from the slave catchers or bounty hunters who wanted to return them to their slave owner
The Secret Dream-lives of Engineers - book - has 26 pages.
The ISBN of The Secret Dream-lives of Engineers - book - is 1-893972-25-9.
The map Harry acquires is the Marauder's Map. It shows where everybody is in Hogwarts, as well as all the different secret passageways. The map was given to him by George and Fred Weasley.