World 6-2 (New Super Mario Bros. 2)
From the Super Mario Wiki, the Mario encyclopedia
The level starts in a volcano-themed overworld; on a ledge above are some coins, and the area underneath leads to a pit that takes the player underground, to the main portion of the level.
After falling down into the area, there is a slope that leads onto a Spine Coaster floating in lava, the segments rising and lowering as it floats along through the level. As the player travels through this area, there are several platforms and blocks overhead containing Goombas that drop down onto the Spine Coaster. After a while, the Spine Coaster stops at a part of land with a Warp Pipe; up above is an alcove with another Warp Pipe leading to a bonus room with a Gold Ring, some POW Blocks, and several Piranha Plants.
On the other side of the Warp Pipe is the Checkpoint Flag and another Spine Coaster after that, this time with a Dry Bones on it; as the coaster travels along, several Lava Bubbles also leap out of the lava. After the Spine Coaster reaches a wall, the lava starts to rise; Para-bombs also start to fall down. After the lava rises to the top, there is a Warp Pipe nearby leading to the outside, to the Goal Pole.