Stasis field

A stasis field was an artificial force field which kept the effects of time and other outside influences from affecting the area within it. As well as that, it kept the inside from affecting the external world.

One such field surrounded Stockbridge in an alternate timeline from 1950 until 2009. The people within relived past experiences every day and could never die, but these effects could not leave the bubble. But, as the Fifth Doctor said, "eventually bubbles pop" — the walls were destroyed and the timeline was negated when the Doctor and Nyssa escaped, thereby never becoming the possible future versions that turned the village into "hell" in the first place. (AUDIO: The Eternal Summer)

The Silence possessed one in 1969, but it was stolen by River Song, along with a perception filter which was being used to hide their base. She used it to keep herself in a state of suspended animation until the Eleventh Doctor found her two centuries later. (GAME: The Eternity Clock)