Super Mario 3D Land Easter eggs

2 Hidden 1-up mushrooms on world 1 level 1!
On world 1-1, if you go down as far as possible then right as far as possible, you will notice a cave blocked by a crate, if you smash the crate then go through the cave you will get a 1-up mushroom then exit the cave go up to the higher part and jump down and right onto the coloured blocks then run down and scare away the bird and another one will appear.