Answer:

ADIT

Answer	Crossword Clue
ADIT	Mine entrance
ADIT	Doorway to ore
ADIT	Entrance

ADIT	This way in
ADIT	Entry or approach
ADIT	Way into a mine
ADIT	Mine access
ADIT	Shaft entrance
ADIT	Mine opening
ADIT	Miner's approach
ADIT	Tram access

ADIT	Ore seeker's entrance
ADIT	Colliery entry
ADIT	Comstock entrance, e.g.
ADIT	Comstock entrance
ADIT	Mine passage
ADIT	Door to ore
ADIT	Entry
ADIT	"His exit is our ..." (Tennyson)

ADIT	Tunnel.
ADIT	Mine entrance.
ADIT	Mine passage.
ADIT	Mining tunnel.
ADIT	Access.
ADIT	Entrance.
ADIT	Stulm.
ADIT	Admission.

ADIT	An approach.
ADIT	Ventilating passage in a mine.
ADIT	Mine tunnel.
ADIT	Ingress.
ADIT	Entrance to a mine.
ADIT	Passage into a mine.
ADIT	Passage leading into a mine.
ADIT	Passageway.

ADIT	Approach.
ADIT	Colliery tunnel.
ADIT	Way into a mine.
ADIT	Opening to a mine tunnel.
ADIT	Tunnel in a mine.