Top 5 teen fantasy series
3. The "Books of Ember" series, by Jeanne DuPrau
There is no sunlight, and day has become a permanent night. This is the world of the citizens of the underground City of Ember. With the electricity generators dying out and food running low, tensions are running high in the city. The instructions for how to return to the Earth's surface have been lost, and it is up to young Doon and Lina to find them before time runs out in this critically lauded series.