Dimensional Gateways are portals or windows both artificial and natural that link and connect separate dimensions and realities separated by dimensional barriers. They can even be used to link separate periods in time to simulate "time travel." The Altrusian race was able to create dimensional barriers using crystal technology to entire and pass through the Land of the Lost for other worlds and dimensions. However, since the fall of their civilization, much of their technology has fallen into disrepair or has been neglected, causing individuals such as the Marshalls to be trapped in the Land of the Lost. One relic known as the Mageti allowed the Altrusians to find these gateways.
Through their history, the Marshalls encountered or accidentally created gateways due to their unfamiliarity with the Altrusian technology. While tampering with the Mountain Pylon, Will accidentally created a loose gateway that brought Beauregard Jackson to the Land of the Lost, and Holly Marshall accidentally summoned her future counterpart in the Lost City. Using what he had learned, Rick Marshall created an unstable gateway that decimated the Land of the Lost and flung him back alone to Earth.
Along with the Marshalls, random gateways also resulted in Jefferson Davis Collie III, Peter Koenig, Harry Potts,Colonel Roscoe T. Post, Captain Reuben Van de Meer, Lone Wolf, Captain Elmo Diggs and possibly Malak and Medusa in arriving in the Land of the Lost.