Editing Grinding-Stone Tower

{{about|Grinding-Stone Tower, a level in [[New Super Mario Bros. U]]|its [[New Super Luigi U]] counterpart|[[Smashing-Stone Tower]]}}
{{level infobox
|title=Grinding-Stone Tower
|image=[[File:NSMBU Grinding Stone Tower Screenshot.jpg|250px]]
|code={{world|6|tower}}
|world=[[Rock-Candy Mines]]
|game=''[[New Super Mario Bros. U]]'' (''[[New Super Mario Bros. U Deluxe|Deluxe]]'')
|powerup=[[Ice Flower]]
|limit=500 seconds
|cr_limit=
|boss=[[Boom Boom]]
|before_alt=
|before=[[Porcupuffer Falls|<<]]
|after=[[Waddlewing's Nest|>>]] [[Light Blocks, Dark Tower|>>]]
|secret=[[Thrilling Spine Coaster|**]]
}}
'''Grinding-Stone Tower''', or '''{{world|Rocky|tower}}''', is the first [[Tower]] of [[Rock-Candy Mines]] in ''[[New Super Mario Bros. U]]''. This level is unlocked via completion of [[Porcupuffer Falls]]. Defeating [[Boom Boom]] in this course unlocks a passage to [[Waddlewing's Nest]] and [[Light Blocks, Dark Tower]], and the tower's secret exit unlocks [[Thrilling Spine Coaster]].

==Layout==
[[File:NSMBU 6-T Boom Boom.jpg|thumb|left|[[Mario]] in the battle with winged Boom Boom.]]
The level begins below a platform with a [[? Block]] and a nearby pipe spawning [[Grrrol]]s. A [[Bony Beetle]] is found, along with two [[Warp Pipe]]s that move upwards and downwards, allowing the player to reach the next platform. More Grrrols are spawned nearby, and a platform with a Bony Beetle and two [[Brick Block]]s is found. A moving Warp Pipe is found, and a hidden opening next to it allows the player to reach a ? Block containing a [[Mini Mushroom]]. An opening containing [[coin]]s is found, allowing the player to avoid nearby Grrrols. After passing by the Grrrols, another sloped platform with a Bony Beetle on it is found, followed by two moving Warp Pipes. A series of platforms with [[Mega Grrrol]]s on them is found, leading to the [[Checkpoint Flag]]. A group of Warp Pipes is found, with a ? Block above it and Grrrols spawning from the right. More sloped platforms and Grrrols are found, and a hidden [[Red Ring]] is found in a wall. After another platform, two ? Blocks are found, followed by multiple moving Warp Pipes acting as platforms and Grrrols. Two Mega Grrrols are found, followed by a platform with a Bony Beetle and the boss door on it.

Boom Boom makes his last appearance in the game as the boss of the tower. [[Kamek|Magikoopa]] swoops in and causes Boom Boom's arms to turn into wings, which allows him to fly and dive into the player.

==[[Star Coin]]s==
{|class="wikitable" style="text-align: center"
|-
!Image
!Location
|-
|[[File:NSMBU 6-T Coin 1.jpg|200px]]
|A [[small pipe]] that leads to the area with the first Star Coin is present at the beginning of the course, to the left. [[Mini Mario (form)|Mini Mario]] is required for this Star Coin.
|-
|[[File:NSMBU Grinding Stone Tower Screenshot.jpg|200px]]
|The second Star Coin is hidden within a wall to the right, after a series of Grrrols and just before the [[Checkpoint Flag]].
|-
|[[File:NSMBU 6-T Coin 3.jpg|200px]]
|Another small pipe which leads to the area with the third Star Coin is present at the end of the course, to the right. As with the first Star Coin, Mini Mario is required to reach this Star Coin.
|}
{{br|left}}

==Secret exit==
[[File:NSMBU 6-T Secret Exit.jpg|left|thumb|The small pipe leading to the third Star Coin and the secret exit]]
Immediately after the third Star Coin is a Warp Pipe that leads to the secret exit. It opens the path to [[Thrilling Spine Coaster]].

==Enemies==
{|class="wikitable" style="text-align:center;border-collapse:separate"
!Image
!Name
!Count
|-
|[[File:NSMBU Grrrol Artwork.png|50px]]
|align=left|[[Grrrol]]
|(infinitely spawned)
|-
|[[File:Dai Goro model.png|50px]]
|align=left|[[Mega Grrrol]]
|12
|-
|[[File:NSMBU Bony Beetle Artwork.png|50px]]
|align=left|[[Bony Beetle]]
|4
|-
|[[File:Boom Boom NSMBU Model.png|50px]]
|align=left|[[Boom Boom]]
|(boss)
|}

==Names in other languages==
{{foreign names
|Jpn=ごろごろゴローのとりで
|JpnR=Gorogoro Gorō no Toride
|JpnM=Fortress of Rolling Grrrols
|SpaA=La Torre de Don Machucón
|SpaAM=Grrrol's Tower
|SpaE=La terrible Torre Cróncher
|SpaEM=Terrible Grrrol Tower
|FreE=Tour Mabroule
|FreEM=Crazy Tower
|Dut=Grrruwelijke Grrrol-toren
|DutM=Brrrutal Grrrol-tower
|Ger=Grrroll-Turm des Grauens
|GerM=Grrrol's terror tower
|Ita=Torre della Pietra stridente
|ItaM=Rough Stone Tower
|Por=Torre Grrroda
|PorM=Grrrol Tower
|Rus=Башня шипокатов
|RusR=Bashnya shipokatov
|RusM=Grrrols castle
|Kor=데굴데굴 데구르 요새
|KorR=Deguldegul Degureu Yosae
|KorM=Rolling Grrrol Fortress
|Chi=滚动刺滚轮的堡垒 (Simplified)<br>滾動刺滾輪的堡壘 (Traditional)
|ChiR=Gǔndòng Cì Gǔnlún de Bǎolěi 
|ChiM=Fortress of Rolling Grrrols
}}

==Level map==
[[File:NSMBU Grinding-Stone Tower Map.jpg|400px|thumb|left|]]

{{NSMBU levels}}
[[Category:Towers]]
[[Category:Mountains]]
[[Category:Levels with a secret exit]]
[[Category:New Super Mario Bros. U levels]]
[[de:Grrroll-Turm des Grauens]]
[[it:Torre della Pietra stridente]]