This is for the episode of The Little Mermaid TV series. You may be looking for the eponymous location."Eel-Ectric City" is the fourteenth episode of the animated series The Little Mermaid TV series, originally aired on December 5, 1992.
When Ariel hears her sister Alana is going to a party at Pearl's house, Ariel shyly asks if she can come along. Pearl says yes, Ariel is excited, Alana decides to give her sister a makeover, and Flounder is skeptical about the whole thing (being a boy and all). Ariel and Alana ask their father for permission to go to the party, and it's granted because King Triton feels that it's okay as long as Pearl's parents will be around to supervise the party.
Later when Pearl comes by the palace to pick the two princesses up, she weasels Ariel into driving Triton's chariot to the party. Ariel and Alana are helpless to deny Pearl what she wants, and off they go. But then it turns out that there is no party at Pearl's house, and Pearl is in fact taking them to Eel-ectric City, the place so hoppin' that it's always boppin'. Flounder finds out about this and recruits Sebastian, so that together they can go after and rescue Ariel, though when they arrive things don't quite work out in the way they planned.