World 8-2 (New Super Mario Bros. Wii)
From the Super Mario Wiki
This level contains more falling debris and spinning wheels on the ground. As soon as Mario and co. enter the pipe, they end up in an underground area filled with more lava. Goombas and Paragoombas appear many times on this stage, along with Spiked Balls. The player has to dodge the obstacles to get through. This level also has a secret exit.
Directly after the second Star Coin, there is an area with several spinning wheels and Spiked Balls. At the end of it, turning left reveals a hidden area that leads to a green Warp Pipe. This Pipe leads to an area with more, faster spinning blocks that can only be traversed by jumping. Once at the end, the player must avoid the Goombas and jump up to the Pipe which leads to the secret flagpole.