Rock Bottom is a small city in a deep-sea trench located beneath Bikini Bottom. The city is first seen in the episode "Rock Bottom" and makes other appearances in the franchise afterwards, but doesn't make its second episode appearance until "Out of the Picture." It has been confirmed that Rock Bottom will make multiple appearances over season ten and eleven.
The road between the two cities is so perfectly vertical that it can only be accessed by a bus or balloon.
Sunlight does not reach this part of the ocean, so everything is always pitch black except for a few street lights. Signs are written in a language based on English, except with the letters distorted, inverted, or in a different orientation. The soil is green with living sludge that can talk. Most residents of Rock Bottom are bioluminescent. They speak a language nearly identical to English, except that they blow raspberries between most words and sentences.
The entry area of Rock Bottom contains a "Kandy" machine. The road leads back to Bikini Bottom and restrooms, although foreigners cannot tell which is the men's room and which is the women's due to the weird symbols used to mark them, and are unable to determine the genders of the inhabitants.
Rock Bottom also has a major bus station, although the bus is extremely hard to catch. There is also an information booth, with extremely long waiting lines. SpongeBob has attempted to be first in line, but the residents scare him so badly that he is forced to be 329th in line.
There is also a police station and a prison, as seen in SpongeBob's Boating Bash. There are many billboards throughout the town. Lastly, the signs on the bathroom doors have question marks on them.
In Employee of the Month, Rock Bottom is the location of the game's second chapter. It also includes a TV network WSEA with weatherman Gary Gulper and a soda bar called the Rusty Anchor, run by a muscular fish named Big Mac. The weather wizard of Rocky Town, named Marlin, lives there.
In Battle for Bikini Bottom, Rock Bottom is the sixth level in the game in order. The main mission of the level is to collect artwork stolen from the Rock Bottom Museum and return them to Mrs. Puff. The player also travels to the Trench of Advanced Darkness, a trench that is lower than the city itself. There is also an episode reference to "Rock Bottom" in the game; if SpongeBob approaches the Kandy Machine, a small cutscene will play and a bus will stop next to the machine, before leaving.
In The Yellow Avenger, this is where the player finds the Flying Dutchman. They can also see the bus station, which is accessible. There is also a Giant Anchor, and a vending machine can be found inside the bus station.
It appears in SpongeBob's Truth Or Square during the 24-hour shift flashback level. It is where the entire level occurs and takes place.
It appears in the game SpongeBob's Boating Bash as a driving area.
Rock Bottom likely has the lowest sea level of any of the cities in the Pacific Ocean since it is located in a trench.
Rock Bottom has an appearance similar to the monster-infested trench on the way to Shell City.
Rock Bottom is most likely located in the Pacific Ocean's hadopelagic zone. If this is the case, then SpongeBob and Patrick, being foreigners to this part of the ocean, should keel over and die as soon as they set foot in the city; the temperature in this zone is often below freezing, and the water pressure should be around 8 tons per square inch.
Rock Bottom makes its second in-series appearance in the season 10 episode "Out of the Picture," marking the city's first appearance in the show 17 years.