Just because The Needle was a vertical dungeon didn't mean I couldn't have under levels. The two main cutaways showed some of the relationship with the deep caverns.
Cutaway A
This is the 'A' cutaway, showing the main upper level areas. There's also an 'A' overlay with more GM's info and additional vertical connectors inked in. I'll post a horizontal slice view of the main entry level where the waterfall pours out. Most groups never hunted for a back door, they found plenty of trouble at the main entry. The 'B' cutaway shows a depth of several miles below The Needle and locations as far down as the Drow city of N'Draka. I'll have to re-scan that to a different format as Google Sites doesn't load pdf's.
Cutaway B
The B version of the cutaway shows several other adventuring regions in local relationship. Parties explored several of the areas and were chased out of the Sea of Darkness by an Elder Horror. Good times... for the GM.
The Drow city of N'Draka has a partially completed map with an overlay to show the web roads over it. Players have gone there several times on trading expeditions and to hunt bargains at the yearly market where the wild Drow tribes gather to sell salvage finds and rare gems from the shores of The Sea of Darkness.