There’s a moment in “Frozen” where you can see Rapunzel and Flynn/Eugene, the protagonists of “Tangled,” arriving for Elsa’s coronation.
Geographically, this isn’t too hard to justify. “Tangled” arguably takes place in Germany (the story of Rapunzel is originally a German fairy tale) and “Frozen” seems to take place in Norway (based on various architectural/cultural nods throughout as well as the Scandinavian setting of its origin fable, Hans Christian Andersen’s “The Snow Queen”).
But why are Rapunzel and Flynn at the party? This is where it gets fun, via a theory presented by Beautiful Syn
The theory posits that Elsa and Anna’s parents from “Frozen” were en route to Rapunzel’s return celebration when their ship sank. As the boat sailed from Norway to Germany, it would’ve passed near Denmark, which is where it sank.
How do we know this? Because you can see the wreckage in “The Little Mermaid,” which arguably takes place around Denmark (it’s another Andersen tale, set in his native land).