The Factory

Smithy's Factory is the last area from Super Mario RPG: Legend of the Seven Stars. It is accsessed by defeating Exor, who will suck you into a portal between Mario's World and Smithy's Factory. In the game, the area is simply called "Factory". As the name tells, Smithy, the final boss of the game is located here.

Music
That area is seperated into two parts. They have different sountracks:

The Portal/Gate Section -

The Factory -