Blue Switch Palace
The Blue Switch Palace is the last of the four Switch Palaces in Super Mario World. It's found in the Forest of Illusion behind the water level Forest of Illusion 2. This level cannot be replayed once it is completed.
The palace consists of two rooms, which the player has 200 seconds on the Timer to complete. The first room contains a blue P-Switch, a silver P-Switch, and a line of Used Blocks with several Spinies walking across the top. The trick is to collect a handful of Coins near the edge of the bottom row first before activating any of the P-Switches. Once that's finished, the player can hit the blue P-Switch to make the top row become coins and the bottom to solid brick. The player should immediately hit the silver P-switch, turning the Spinies into Silver Coins. Then the player should quickly jump onto the solid bottom row and collect as many top-row coins as possible. If all the silver coins are collected, the player gets an Extra Life. Once the P-switches wear off, the player can freely collect the bottom row before continuing to the next room. The player is not forced to hit either P-Switch to progress through the level, however.
The second room is empty except for the blue ! Switch, which can be activated by jumping on top of it.
 Gameplay Effects
Once the blue ! switch is hit, all the blue Dotted Line Blocks will become blue ! Blocks. The blue ! Blocks help the player progress through the levels by filling in gaps and allowing some secret exits to be reached.
 Levels with Blue ! Blocks
Blue ! Blocks can be found in these levels: