Room 11 (The God Complex)

Room 11 was a room in a Prison Ship disguised as an Earth Hotel. Room 11 was The Doctor's Room, which contained The Doctor's Worst Fear. When he looked inside it, he heard TARDIS's Cloister Bell ringing, as The Doctor remarked "Of course. Who else?". (TV: The God Complex)

When The Doctor was on Trenzalore, he saw a crack in time inside the clock tower. It is revealed that the object he saw in Room 11 was the crack in time, created from the Total Event Collapse. (TV: The Time Of The Doctor)