Super Mario 64/Tower of the Wing Cap

When Mario has collected 10 stars, a bright light in the castle main room will appear. Stand in the light, with Mario facing the stairs and look up. Mario will then enter the level.

The level is basically composed of five towers: four small ones and a large one. On top of the large one, you will find the button that activates the red cap blocks.

Collect 8 red coins
The eight red coins are placed in pairs in the air around the towers. Fly round and round to get them. Press Z if you don't get both of them in one run. (Except if you have got 3 pairs of red coins. If you have, land on the central pillar and triple jump to get the last coin.) You will need to use the wing cap to collect them. One pair is so high up in the air that you can't land before you collect them.