10 Most Iconic Alien Planets In Modern Doctor Who
4. The Library
A planet-sized library housing every book ever written, the Felman Lux Foundation Library was an ingenious, awe-inspiring sight and the location of 2008's two-part adventure Silence in the Library/Forest of the Dead.
Installed above its vast skyscrapers and expressways was an artificial moon - a Doctor Moon - which acted as a security system. With a whole city of books, reading rooms, reception halls and gift shops, this was the dream travel destination for all bookworms. However, those visiting the Library would also find something else there - the Vashta Nerada.
Flesh-eating 'piranhas of the air', the Vashta-Nerada lived in the shadows, devouring anyone who crossed into the darkness. Realising that its patrons were at risk, the Doctor Moon sealed the Library and 'saved' everyone to the planet's data core.
One-hundred years after the quarantine, the Tenth Doctor visited the Library on request from his future wife River Song. Together they worked out that the Vashta Nerada hadn't invaded - they'd hatched.
Claiming the Library to be their 'forest', the shadows had hatched from the spores in the paper-edition books made from the wood of their home.
The Doctor struck a deal with the Vashta Nerada to allow them to roam the Library-world, as long as he could return all of the stored inhabitants first. Agreeing, the shadows returned to the darkness to allow the Doctor to work. Unfortunately, in order to return the inhabitants to the Library, River Song chose to sacrifice herself to provide the computer with enough memory to operate.
The Doctor then left River Song's diary, featuring her adventures with him, in the Library as just another story for someone to read.
Intergalactic Travel Advice: Spoilers.