Notion Club Revival Challenge: Cave System Map - List of Features (progressing roughly north and east of the mouth)
http://www.silmarillionwritersguild.org/images/challenge/notion-club-revival/cave-map.png

Mouth
Hammerfall Avenue
Mithril Way
Dribble Dome
Queen's Ramble
Labyrinth
Desert Arch
Lost Avenue
Rotunda
Sparks Avenue
River Hall
Trickling Avenue
Quickstep Avenue
Styx
Lethe
Great Walk
Hospitality Avenue
Hamhand Hall
Tinúviel's Bower
Little Bat Avenue
Mammoth Dome
Star Chamber
Araw Avenue
Black Chamber
Great Isle
Flint Dome
Iron Pit
Canter Avenue
Arrow Avenue
Cascade Hall
Solitary Chambers
Stumbling Pit Branch
Chief City
Blue Spring Branch
Moonrise Dome
Skyless Dome
Ultimate Dome
Purgatory
Echo River
Durin's Avenue
Fallen Avenue
Roaring River
Tanglestone Avenue
Ulmo's Cups
Snake Tongue Fork
Moonlight Arcade
Bird Avenue
Marble Vinyard
Honeycomb
Tower Island
Tower Island Avenue
Adamant Cabinet
Glow Worm Avenue
The Spurs
Squiggle
The Narrows
Elmo's Rotunda
Sandstone Avenue
Prow Fork
Club Hall