Dimensional portal

A dimensional portal is a construct, either naturally occurring or artificially constructed, which can bridge the distances between one dimension and another. Dimensional portals are most commonly found in the science fiction and fantasy genres.

In film

 * 2001: A Space Odyssey: When the space exploration vessel Discovery One encountered the Monolith artifact near Jupiter, scientist Dave Bowman was pulled into a dimensional portal that forced an evolutionary change upon him, converting him into the Star Child.
 * Xtro 2: The Second Encounter: A team of scientists developed a means to travel to another dimension. After journeying through the gate, all communications between them and Earth were cut off and they were forced to return. A predatory alien species followed them back through the portal and began slaughtering the rest of the research team.