Widowed
forest ranger Rick Marshall and his two children, Will and Holly, are enjoying a
rafting trip when they accidentally fall over a waterfall during an earthquake.
Instead of being instantly killed, they somehow fall through a dimensional
doorway into a closed universe populated by dinosaurs, ape men known as Pakune,
and a race of lizard like men known as Sleestacks.
The Marshall's make
the most of their time in this unknown realm as they try to find a way home for
the next two years by using a monolithic chamber known as a pylon which acts as
a doorway to other worlds. However, one day, Rick tries to use one of them to
get back home and disappears. Rick's brother, Jack, who has been searching for
them lands in the Land of the Lost and joins his nephew and niece in trying to
get back home.