On the head of a pin

Purgatory.
Dean was all alone. Or at least he hoped so. Cas had told him that this is where all evil things go after they die, but so far Dean hadn’t seen any and he hoped that it would stay that way until he found a way out. ‘Cause that was one thing he was certain of. He was going to get out of here and then he would find Cas and kill him.
How could Cas do this to him? Dean had forgiven him for his betrayal, he had given him a second chance and what did Cas do to thank him? He left him at some dark place where he most likely would be ‘ripped to shreds’, to say it with Cas’ words....

Castiel also possesses the ability to bend time and teleport himself and another backwards through time. Perhaps Castiel's most impressive ability observed to date was his removal of Dean's soul from Hell and the apparent resurrection of Dean that followed. Apparently, Castiel is not only capable of entering and exiting Hell at will and without harm, but also of extracting a particular soul in the process. Castiel also appears to be capable of projecting at least a portion of his true self from his host, as at the end of "Lazarus Rising", he was able to display the shadows of his wings to Dean...