Land of the Lost (1974–1976) is one in a variety of popular, uniquely produced children's television series created and produced by Sid and Marty Krofft. The prolific Krofft team was very influential in children's television, producing many oddly formatted, highly energetic, and special-effects heavy programs.

Krofft Productions did a remake of the series in 1991, also titled Land of the Lost.

Land of the Lost detailed the adventures of a family of three (father Rick Marshall, young son Will, and younger daughter Holly) who are trapped in a primitive alien world inhabited by dinosaurs, chimpanzee-like cavemen called Pakuni, and reptilian humanoids called Sleestak. The episode plots focused primarily on the family's efforts to survive and find a way back to their own world. Though the central characters are different, the title indicates that the series may have drawn inspiration from the similar theme of Sir Arthur Conan Doyle's The Lost World.

The series is notable for having a much darker tone than most children's series, and for having a grander and more epic storytelling vision than most shows aimed at children. The relatively complex plots, unique internal mythology, and ambitious special effects (considered very unrealistic and campy today but advanced for Saturday morning TV in the 1970s) have earned the show a large popular following, particularly among adults who watched the show and other Krofft productions as children.

Many Krofft shows involved similar plots, often including children accidentally trapped in other worlds or quirky variations on superhero stories.

The Marshalls are brought to the mysterious world by means of a time portal, a device used frequently throughout the series and a major part of its internal mythology. Though the term "time doorway" is used through the series, the "Land of the Lost" is not meant to portray an era in Earth's history, but rather (like Doyle's The Lost World) to be an enigmatic zone whose place and time are unknown. The original creators of these time portals were the ancestors of the Sleestak, called Altrusians, and the portals and the related pylons have mysterious and unpredictable powers, sometimes opening and closing unexpectedly. This results in the Land being populated with a large and ever-growing variety of visitors and castaways.

Outfitted only for a short camping trip, the family must take shelter in natural caves and improvise the provisions and tools that they need to survive. Their most common and dangerous encounters are with dinosaurs, particularly a tyrannosaurus rex they nickname "Grumpy" who frequents the location of their cave. They also tangle with menacing Sleestak and morally ambiguous "cave-men" called Pakuni (one of whom, Cha-Ka, they befriend), as well as a variety of other dangerous creatures, mysterious technology, and strange geography.

The main goal of the three is to find a way to return home. They are occasionally aided in this by the Altrusian castaway Enik. At the start of the third season Rick Marshall unexpectedly returns to Earth, leaving his children behind, and is replaced by his brother Jack.

- From Wikipedia