Editing World D-4

{{image|more=yes|Needs in-game screenshot from the original FDS version}}
{{level infobox
|title=World D-4
|image=[[File:SMAS LL World D-4 Screenshot.png]]
|code=D-4
|world=[[World D]]
|game=''[[Super Mario Bros.: The Lost Levels]]''
|limit=400 seconds
|before_alt=
|before=[[World D-3|<<]]
|after=
|secret=
|boss=[[Impostor Bowser|Fake Bowsers]] ([[Spiny|Spinies]]) <small>([[Bowser's Brother]] and [[Bowser]] in ''All-Stars'')</small>
|track=[[Shiro BGM|Castle Theme]]
|sample=[[File:SMB Castle Theme.oga]]
}}
'''World D-4''' is the fourth and final level of [[World D]] in ''[[Super Mario Bros.: The Lost Levels]]'' and the twentieth and final secret level overall in said game, as well as the final level in the game overall. Like with [[World 8-4 (Super Mario Bros.: The Lost Levels)|World 8-4]], lightning flashes in the background of the level and the level's title card in ''[[Super Mario All-Stars]]''.

==Layout==
The player starts in a room similar to that the one at the start of 8-4. The player has to jump across a pit of [[lava]] while avoiding a long [[Fire Bar|Fire-Bar]], then while avoiding another Fire-Bar at the end of the corridor, the player can find a power-up in a [[Hidden Block]] against the wall. Jumping across a lava pit with a [[Lava Bubble|Podoboo]] jumping out and avoiding the next Fire-Bar, the player then has to bounce off of a [[Koopa Paratroopa]] and avoid pipes with [[Piranha Plant]]s, along with [[Cheep Cheep|Cheep-cheep]]s that jump out of the lava until the player reaches the next hall. After a falling [[lift]] and a Fire-Bar, the player will find a [[Warp Pipe]] at the end of the hallway.

The next area is an overworld area, with the first enemy being a charging [[Hammer Bro]]ther. After the second pipe with a Piranha Plant, [[wind]] will begin blowing. The player will next encounter two Koopa Paratroopas, two [[Blooper|Bloober]]s, another Piranha Plant, and a hidden [[Poison Mushroom]] before a flight of stairs, which the wind will stop blowing beforehand. After a jump across a large pit, the player will find a Warp Pipe with a Piranha Plant.

The third area is a simple underground chamber with [[Coin]]s and a [[Coin Block]] above the start of the third row of Coins.

The fourth and final area has the player return to the castle, where they will encounter a [[Impostor Bowser|fake]] [[Fire Breath|fire-breathing]] [[Bowser's Brother]] (or in the case of ''All-Stars'' the actual Bowser's Brother who only throws [[hammer]]s). Above him is a row of [[? Block|?]]s, with the fifth from the right containing a power-up. The next Warp Pipe with the Piranha Plant and Bloobers surrounding it will take the player back to the start of the level. After the pipe is a Hammer Brother, followed by a narrow passage that the player will have to [[crouch]] and slide through if they are in a [[Super Mario (form)|Super]] or [[Fire Mario|Fire]] form. Using a lift to get up over a ledge, the player then has to time a fall into a narrow passage while avoiding a Podoboo. Finally, the player will encounter a [[Impostor Bowser|fake Bowser]], who throws breathes fire and has a Fire-Bar above him (in ''All-Stars'', this was replaced by the actual Bowser himself who only throws hammers). Upon defeating him or touching the [[axe|ax]], the player will save [[Princess Peach]] and complete the game.

==Enemies and obstacles==
{{Number of enemies
|image1=[[File:SMBLL Red Piranha Plant.png]]
|name1=[[Piranha Plant|Red Piranha Plant]]
|count1=10
|image2=[[File:FireRodSMB.gif]]
|name2=[[Fire Bar|Fire-Bar]]
|count2=5
|image3=[[File:Podoboo Sprite SMB.png]]
|name3=[[Lava Bubble|Podoboo]]
|count3=2
|image4=[[File:SMB Red Koopa Paratroopa Sprite.gif]]
|name4=[[Koopa Paratroopa|Red Koopa Paratroopa]]
|count4=1
|image5=[[File:SMB Swimming Cheep Cheep Sprite.gif]]
|name5=[[Cheep Cheep]] (Red)
|count5=(infinitely spawned offscreen from the bottom in the first area)
|image6=[[File:SMB Hammer Bro Throwing Hammer Sprite.gif]]
|name6=[[Hammer Bro]]
|count6=2
|image7=[[File:SMB Green Koopa Paratroopa Sprite.gif]]
|name7=Green Koopa Paratroopa
|count7=2
|image8=[[File:SMBLL Sky Bloober.png]]
|name8=[[Blooper|Sky Blooper]]
|count8=5
|image9=[[File:BowserBrotherSMBTLL.png]]
|name9=[[Impostor Bowser|Fake]] [[Bowser's Brother]] ([[Spiny]])
|count9=1 (mid-boss, FDS only)
|image10=[[File:SMAS SMB Bowser Sprite.png]]
|name10=Bowser's Brother
|count10=1 (mid-boss, SNES only)
|image11=[[File:SMB Bowser Breathing Fire Sprite.gif]]
|name11=Fake Bowser (Spiny)
|count11=1 (final boss, FDS only)
|image12=[[File:SMAS SMB Bowser Sprite.png]]
|name12=[[Bowser|Bowser, King of the Koopa]]
|count12=1 (final boss, SNES only)
}}

==Items==
{{Item locations
|image1=[[File:SMBCoin.gif]]
|name1=[[Coin]]
|count1=47
|notes1=15 in [[? Block]]s, up to 10 in one [[Coin Block]], and 22 in open air.
|image2=[[File:SMBLL Super Mushroom Sprite.png]][[File:Fire Flower SMB.gif]]
|name2=[[Super Mushroom|Mushroom]]/[[Fire Flower]]
|count2=2
|notes2=
|image3=[[File:SMBLL Poison Mushroom Sprite.png]]
|name3=[[Poison Mushroom|Poisonous Mushroom]]
|count3=1
|notes3=Hidden in an [[Hidden Block|invisible block]].
}}

==Level maps==
{{Wide image|NES LL World D-4 Map.png|6160|Map of World D-4}}
{{Wide image|SMAS LL World D-4 Map.png|5696|Map of World D-4 (''[[Super Mario All-Stars]]'' version)}}

{{SMBTLL levels}}
[[Category:Bowser's castles]]
[[Category:Super Mario Bros.: The Lost Levels levels]]