Energy barrier

An Energy barrier was used by the Silurians to trap the occupants of Cwmtaff within it.

It was invisible to the naked eye, but could be shown if it was hit, or when shown by the Doctor's sonic screwdriver.

The barrier was red in colour and did not allow people pass through it. It did, however, allow rain to pass through. It could also block out light, making it seem as though it was during the night. (DW: The Hungry Earth)