Undercity Catacombs

 Dungeon Parts

Secret Room

Tips Dungeon Parts

Secret Room

Tips

Lower Floors

 * Floors 1-20

Upper Floors

 * Floors 21-30

Pokémon
The Pokémon here are Ground, Ghost, Dark, Steel, Rock-type.

Lower Floors
 

Boss

 * Onix (2)


 * Steelix

Ending Box

 * Ekop
 * Relic Copper
 * Relic Silver
 * Relic Gold
 * TM Payback
 * King's Rock
 * Psyche Dust
 * Reaper Cloth
 * Invisify Orb
 * Max Revive
 * Purple Bow
 * Restore Power
 * Rotten Apple
 * Metal Coat
 * Shiny Stone
 * Purple Gummi
 * Revive
 * Invisify orb

Secret Room
There are 2 boxes in the secret room. The boxes may contain the following items:
 * Moon Stone
 * Sun Stone
 * Dusk Stone

(The list is incomplete, so feel free to edit it.)
 * Relic Vase
 * Lum Berry
 * Lunar Ribbon
 * Relic Copper
 * Shadow ball
 * Max reviver
 * Revival Herb
 * Rare fossil
 * Max potion

Tips
2-3-7 is the fastest route through the puzzle on floor 20