Looking for Books About Rediscovering the Past

[travelgirlut]

I love reading books where civilization has forgotten their past and then goes on to rediscover all they've forgotten, books such as The City of Ember, Off Armageddon Reef and series, Battlefield Earth, parts of Asimov's Foundation series, even the Dragon Riders of Pern series. I prefer more of a sci-fi feel to the book rather than fantasy, but I'll read either.

So I'm looking for all your suggestions along these lines. Thanks!