make a place which can be accessible only with small players

[RudeGuy]

I want to know it for a gimmick. Also I would that place can be accessible with princess Peach too.

[Karl Marx]

I would recommend a one block entrance, but that can easily be circumvented if the player has a power up.

Maybe if you stick spikes out the entrance so the player is forced to take the hit, but provide a mushroom block, so the spike doesn't kill the player if they don't have a powerup

[RudeGuy]

If the player is in the super form he'll can't entrance in that place.

[Karl Marx]

If the player is in the super form he'll can't entrance in that place.

Maybe if you stick spikes out the entrance so the player is forced to take the hit, but provide a mushroom block, so the spike doesn't kill the player if they don't have a powerup

[RudeGuy]

Please lock, I solve my problem.