Disney’s habit of reusing artwork in its animated features, as well as the deliberate cross-promotion of characters, has led fans on internet forums to connect three stories: Tangled, Frozen, and The Little Mermaid. Although actual geographic locations are not given, they are implied, so the fact that Rapunzel is seen attending Elsa’s coronation led some to think that Anna and Elsa’s parents’ ship sank on their way to Rapunzel’s wedding. And that was the shipwreck that Ariel plunders to learn about humans.
The theory makes sense, although when I was young, I considered Hans Christian Anderson's The Snow Queen (on which Frozen is supposedly based), to be more of a North Pole tale, set in Spitsbergen, Lapland, and Finland, as well as Norway. A roundup at Buzzfeed explains it all with maps and images.