The Waterfall was one of the locations on the Island, first encountered by Kate and Sawyer ("Whatever the Case May Be") and later by Nikki and Paulo. ("Exposé") It was also the location where some of the survivors of Flight 316 landed. According to Jin it was located in grid 134 ("316") A different waterfall was also seen when Michael went on a search for Walt. ("...And Found")
In "Whatever the Case May Be", while collecting fruit for the camp, Kate and Sawyer heard the sound of falling water. Following the sound, they found a waterfall spring, which they descended into and later used the surrounding rocks to dive in again. While diving, they found the bodies of two dead Flight 815 passengers underwater, still strapped to their seats. Sawyer decided to search the passengers for any goods they might have had on them and he found a wallet. Kate found Edward Mars's Halliburton case trapped under the seats and enlisted Sawyer's help to fetch it.
Paulo finds the bag in the waterfall pool.
In "Exposé", during an on-Island flashback, Nikki overheared Kate discussing the guns from the Halliburton case with Dr. Arzt and Shannon, and asked Kate where the case was found. Nikki and Paulo visited the waterfall, where Paulo dove to the bottom to look for their missing bag, containing their diamonds worth over $8,000,000. He found the bag, but told Nikki that there were only dead bodies in the water. Paulo later returned to the waterfall in secret and retrieved the bag.
Jack and Hurley at the waterfall.
Jack, Hurley, and Kate were transported to locations near the waterfall on the Island in 1977 after disappearing from Ajira Airways Flight 316 in a time flash that took them some 30 years back in time. Jack landed in the jungle above the waterfall, while Hurley appeared in the waterfall lagoon, and Kate crashed atop some rocks at the edge of the lagoon. Moments later, a DHARMA van arrived on the scene, and the driver got out and momentarily pointed his gun at the three. The driver was revealed to be Jin, and he lowered his gun upon recognizing them. ("316")
- After Michael left the Tailies, he was found by Eko and Jin at the base of a small waterfall screaming wildly for Walt. ("...And Found")
- The Tunnels were reached through an entrance behind a waterfall. ("Follow the Leader")
Another waterfall in "...And Found".
- After Jack saved the Island by placing the plug back in the Source at the Heart of the Island, he soon afterwards woke up next to a small waterfall nearby. Severely bleeding from his knife wound, he got up and started walking through the bamboo grove where he died. ("The End")
The Lost-based semi-canonical novel Signs of Life featured a waterfall (presumably the one discovered by Kate and Sawyer) which Jeff Hadley used as a landmark on the way to the set of caves where he was later attacked, along with Michael, by polar bears.
- The filming location from "Whatever the Case May Be" is Waimea Falls in the Waimea Valley Audubon Center in Hawaii.
- The filming location of the underwater scenes is the dive pool at the Hawthorne City Pool .
- The filming location from "...And Found" where Michael screams for Walt is in Waihee Valley in Hawaii