From the back cover:
The dungeon is home to the monsters, which live within, and they guard it with their lives. Some will enjoy the excitement and variety a party of delvers brings, some will be openly hostile and fight with all the power they can muster. The entrance lies within the jagged rocks of the Doom crags, a wicked range of mountains far to the north of the land. Goblin Crag lies directly beneath the highest point of the mountains, a point named The Dragon Tooth. A cave in the rocks about a day's trek from the base of the mountains marks the entrance, which is gained via a dark tunnel at the rear of the cave, which after around a quarter of a mile becomes another small cavern, in the floor of which is set an iron trapdoor; this opens to reveal a dark chimney of man-made origin, leading down for 60' to another trapdoor, which in turn drops into room 1 of the first level of the dungeon. The chimney has a strong iron ladder set into the side.