Oh, good example. Come to think of it there must be other time-travel stories which fulfil the spirit of "finding out about the past" even if there's 'magic' involved. Asimov's Ugly Little Boy. And surely I can think of others though I can't right now.

ETA: And I guess there's the reverse, like Da Vinci Code, where what's uncovered may or may not be magic, but is a matter of "ancient secrets which we need to re-learn"...