Indonesia is a country situated in Southeast Asia and is the world's largest archipeligac state, with 17,508 islands according to government estimates. The region was an intrinsic part of the false story given by the Oceanic Six, detailing the supposed crash of Oceanic Flight 815 off the coast of Bali.
It is said by Naomi that Oceanic Flight 815 crashed into an ocean trench off the coast of Bali. In the alternate reality game Find 815, Sam Thomas confirms this by locating the wreckage in the Sunda Trench, which is near Bali. However, it is later revealed that the wreckage was staged by Charles Widmore.
Membata is believed to be a fictional Island (though in the show it is addressed as uncharted). An uninhabited location, it is used as part of the cover-story to explain how the Oceanic Six survived the crash. According to a spokeswoman during the Oceanic Six press conference, the plane crashed near the island, and currents pulled a number of survivors to the shore. There they lived for 108 days. ("There's No Place Like Home, Part 1")
According to the above mentioned cover story, after staying on Membata for over one hundred days, a typhoon caused a boat to also reach the Membata shore. With supplies onboard, the survivors used the boat to reach the real island of Sumba, where they allegedly made contact with locals in the village of Manukangga.
The Ajira Airways website announces a new service from Los Angeles to Honolulu to Guam to Indonesia, although it does not specify which city in Indonesia. Ajira Airways Flight 316 may fly part or all of this route.