Well, I am going to teach you (the one who's reading this) the 3 ways to reach bowser's castle, if you know more ways please send me a private message. Some of them might be harder then the normal way so be careful while trying to do the impossible:
1: Use the star road: in donut plains take the key in the first zone and in the water level, then find a way to reach and defeat the big boo in the secret haunted house, if you do defeat him a star will appear in the map and you will be teleported to the star road. To pass the levels you need to find the secret keys, cause if you reach the "finish line" you will only go back to the start. At some point when you enter the bottom-right star you will be in bowser's lair and the patch for the castle will be unlocked, it don't take much time and you can find colored yoshis in the star zones. The other stars can be used in the same way but it takes more time to find them, the others can be found in: Vanilla dome secret #1, Soda lake (butter bridge secret zone), Forest of illusion's fortress and in Bowser's cave, but you don't need to enter the star to unlock the castle in this one (3rd item will explain why)
2: Bowser lair secret fortress of doom: after reaching bowser's secret cave, take the key in the second zone and it will take you to a fortress, I think the fortress is the hardest level in super Mario world but if you pass trough it you will be able to reach the "back door", wich will make you start bowser's castle in the dark area, making much easier to reach the final boss.
3: Star teleport trick: in bowser's cave there's a red-colored zone wich requires yoshi to take the key, if you get it you will be teleported to the star road again, but you don't need to pass trough any level there, I don't really like this way cause you only skips the 7th castle.
Of course, you can take the normal way to go, wich will follow the original storyline but if you're in a hurry you can use those 3, I hope I helped you. Bye.
Well, I am going to teach you (the one who's reading this) the 3 ways to reach bowser's castle, if you know more ways please send me a private message. Some of them might be harder then the normal way so be careful while trying to do the impossible:
1: Use the star road: in donut plains take the key in the first zone and in the water level, then find a way to reach and defeat the big boo in the secret haunted house, if you do defeat him a star will appear in the map and you will be teleported to the star road. To pass the levels you need to find the secret keys, cause if you reach the "finish line" you will only go back to the start. At some point when you enter the bottom-right star you will be in bowser's lair and the patch for the castle will be unlocked, it don't take much time and you can find colored yoshis in the star zones. The other stars can be used in the same way but it takes more time to find them, the others can be found in: Vanilla dome secret #1, Soda lake (butter bridge secret zone), Forest of illusion's fortress and in Bowser's cave, but you don't need to enter the star to unlock the castle in this one (3rd item will explain why)
2: Bowser lair secret fortress of doom: after reaching bowser's secret cave, take the key in the second zone and it will take you to a fortress, I think the fortress is the hardest level in super Mario world but if you pass trough it you will be able to reach the "back door", wich will make you start bowser's castle in the dark area, making much easier to reach the final boss.
3: Star teleport trick: in bowser's cave there's a red-colored zone wich requires yoshi to take the key, if you get it you will be teleported to the star road again, but you don't need to pass trough any level there, I don't really like this way cause you only skips the 7th castle.
Of course, you can take the normal way to go, wich will follow the original storyline but if you're in a hurry you can use those 3, I hope I helped you. Bye. 
User Notice 
