Bikini Atoll is the marker of where Bikini Bottom is located. It makes its first episode appearance in "Home Sweet Pineapple."
Its most notable landmarks are the three trees that inhabit one side of the island. It appears small, but in reality, it is much larger and appears small because of an optical illusion.
On the other side of the island there is a forest filled with an array of wild life and a skeleton who formerly guarded the Magic Book.
Bikini Atoll has been around for millennia. The trees that inhabit the island have had its ancestors during the times of prehistory.
At one point, Davy Jones was either on the island or at least had the Magic Book which formerly resided on the island. 
- In "Big Pink Loser," the island appears when Patrick jumps out of the water to tell it about "his" newly attained award, only to almost suffocate from lack of water moments later.
- The island appears in The SpongeBob SquarePants Movie when Hasselhoff arrives with both SpongeBob and Patrick to bring them back to Bikini Bottom.
- The island appears in "Truth or Square" when Patchy goes looking for SpongeBob, who didn't arrive at his TV Extravaganza.
- The island appears in "Mall Girl Pearl" in Beatrice's scrapbook.
- The island appears in SpongeBob SquarePants featuring Nicktoons: Globs of Doom as a secret area to get a Krabby Patty Trophy.
- Bikini Atoll was an island that was used for nuclear bomb testing in the 40s and 50s.
- Starting with "Lame and Fortune," a CGI model of the island is used instead of the filmed island.
- This is because the original model island is buried somewhere deep within the Hillenburg Storage Facility, where he rents to pile things that he doesn't have room for in his house.
- When the island is shown at night, a human finger is visible in the water to portray a reflection of the moon. This is because the island was originally shot in Steve Belfer's pool.