As Vishvesh says, the trapdoor and Fluffy are located in a corridor. Once they go through the trapdoor, they need to make their way through passageways and through rooms which have the obstacles in them. The rooms themselves don't seem to have names, but Harry refers to "the flying-key room":
'No, listen - get back and get Ron - grab brooms from the flying-key room ...'
Harry Potter and the Philosopher's Stone - pp.207-8 - Bloomsbury - Chapter 16, Through the Trapdoor
And the chessboard is within a room:
The next chamber was so dark they couldn't see anything at all. But as they stepped into it, light suddenly flooded the room to reveal an astonishing sight.
Harry Potter and the Philosopher's Stone - p.204 - Bloomsbury - Chapter 16, Through the Trapdoor
What we do know is that the trapdoor gave them access to the dungeons and all of these rooms and passageways were part of Hogwarts' dungeon complex:
'What happened down in the dungeons between you and Professor Quirrell is a complete secret, so, naturally, the whole school knows.'
Harry Potter and the Philosopher's Stone - p.214 - Bloomsbury - Chapter 17, The Man with Two Faces