Airway (Mario & Luigi: Bowser's Inside Story)

The Airway is the final area of Bowser's body that Mario and Luigi explore in Mario & Luigi: Bowser's Inside Story and its 3DS remake, Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. It is unlocked when the Pump Works is completed. It is apparently located in Bowser's lungs and trachea. This area houses all of Bowser's DNA and is the place where the Dark Star is fought. In order to progress through the Airway, Bowser must inhale a stream of ice from (the now-frozen) Blizzard Midbus's snout, which freezes the entire area, and the player must alternate between two temperature states to reach the end of the area. The player also needs to make use of Liftoglobins to traverse through the area, and must complete a timed minigame hosted by the Totemglobin.

As the Mario Bros. travel through the Airway, the Dark Star slowly progresses through and takes in Bowser's DNA as it goes through. First, it acquires his fist to punch, then his flame breath (with a different flame color), and finally his shell to ground pound, using them to escape the intended traps in the area. When the brothers finally reach and corner the Dark Star in a specific area, it already has absorbed enough of Bowser's DNA to turn into a dark copy of him, albeit in a incomplete, ghostly form due to its power being drained by Fawful earlier, and escapes Bowser's body after fighting Mario and Luigi.

The Emoglobin that hosts the Gauntlet in the Challenge Node suggests that players that want to level up very quickly should battle the monsters in the Airway.

Enemies

 * Air Cheep
 * Stonk
 * Airnapse
 * Air Cannon
 * Dark Star (boss)
 * Dark Satellmite (appears during the boss battle)

Items
Here is a list of overworld items found in the Airway in Mario & Luigi: Bowser's Inside Story. The fourth scene from the start is a hub, and so is the one to the right of it, which will be denoted 0. The scene to the right of scene 0 will be denoted 0R and the one to the upper of it will be denoted 0U.

Beans
There are 8 beans in total in this area.
 * Area with bouncing platforms in the lower area of the map: 
 * Timed challenge area in the eastern area of the map: 
 * By the left water spout in the room above 0U: 

Trivia

 * If the player saves while the Dark Star is in the Airway, the last sentence in the save message says that the Airway is called the Air Space, the Japanese name for the Airway. This was corrected in the remake, where the save message's last sentence now calls the Airway by its English name.
 * This is the only large area in Bowser's body without Attack Pieces.
 * Dreamy Mount Pajamaja, an area from Mario & Luigi: Dream Team, features a similar concept to the Airway. In said area, the player has to freeze and thaw out geysers to advance.