Pulk/Pull Revolving Doors

There are barn doors

And there are revolving doors

Doors on the rudders of big ships

We are revolving doors

There are doors that open by themselves

There are sliding doors

And there are secret doors

There are doors that lock

And doors that don't

There are doors that let you in

And out

But never open

But they are trapdoors

That you can't come back from