Mew can be found at Deep Mystery Jungle (Japanese: ミステリージャングル おくち), guarding the Grass Cornet.
All stages of the Grass-type starters that have existed as of Generation IV are found in this dungeon.
In Explorers of Time and Darkness, Wonder Mail password is the only way to unlock this dungeon; in Explorers of Sky it can be unlocked via Spinda's Café. Once the player has cleared Crevice Cave and obtained Secret Rank, the following codes can unlock this dungeon.
The jobs are ranked E and ★2 through ★7 by default, depending on the floor.
The following floor layouts are used in this dungeon:
Large-sized with 3-12 rooms on floors 12 through 16 and 23 through 29
Medium-sized with 3-9 rooms on other floors, except floors 1 and 7 where it's 3-8 and 3-7 rooms instead, respectively
The amount of items on the floor varies depending on floor:
1-4 on floors 1, 6 and 29
2-5 on floors 2, 4, 5 and 7
3-6 on other floors
There is 6-9 items buried in the walls, but only on floors 1 through 15. There's 2-3 starting enemies on floors 1 through 3, 2-4 on floors 4 through 6, and 3-5 on later floors.
The IQ Booster activates on every floor. Turn limit is 1000. Enemies in the dungeon have 331IQ, while Mew has 330IQ. There is light darkness on floors 1 through 14 and heavy darkness on floors 15 through 29. The items here have 3% chance to spawn sticky.
This is one of the few dungeons to use two secodary tile types, specifically:
Water on floors 1, 2, 3, 6, 8, 9, 10, 11 and 14
Air on floors 16, 18, 19, 21, 22, 24, 25, 27 and 28
Weather on floors 7, 8, 17 and 18 is fog. Weather on floors 5, 10, 15, 20 and 25 is random every time.
Like other Seven Treasures dungeons other than Sky Stairway, stat boosting items and Lost Loot is buried in the walls (in contrast to most dungeons which only have Poké). This is also the only one of these dungeons to have Kecleon Shops.
Each time player enters a floor, only 14 of the species that can be found on a given floor will be chosen. The unpicked Pokémon's spawn rate will be added to whichever picked Pokémon is next in the National Dex order, going back to the beginning if needed.