Bikini Bottom is an undersea city-state where SpongeBob and his friends live. According to Nickelodeon's program summary, Bikini Bottom is located in the Pacific Ocean, beneath Bikini Atoll in the Marshall Islands.
SpongeBob SquarePants and Patrick Star are leaving the Bikini Bottom for a new trip to Australia as they landed in New South Wales on a tour guide around in Sydney and the Outback as they slept in the camp before they explore around the Sydney Opera House as well as Bondi Beach before the two are preparing to return home to the Bikini Bottom.