The door of durin.

[Galadriel55]

Why exactly are we out of the blue suspecting Celebrimbor of double-dealing?

Originally Posted by Nerwen

And it cannot get out.

Well, that's the whole point, isn't it? We might as well find out that the Endless Stairs were "really" made by Dwarves. And all these abysses were made in order to keep their Elf prisoners from escaping. And Mr. Balrog was of course their secret weapon.

Absurd? I rather thought so.