Valmiki did not write Ramayan, he NARRATED it ... he was alive during the time of Ramayan, in fact Ram's sons - Luv and Kush were born in his ashrama , the Sage Valmiki met Ram, Sita, Hanuman - all the characters ...
Plus the proof of ram is all over India in the form of geographically annotated places like Ayodhya, Chitrakoot, Kishkinda, Rameswaram ...
(even Ram Setu - you should refer to the report by Geological Survey of India, which was presented before Madras High Court and it ruled that Ram Setu was man-made, in the Supreme Court WITHOUT ANY EXCAVATIONS, the ASI said it was natural - thus the controversy - anyway, new excavations will take place and the truth will prevail)
But since these events took place 6500 years ago (yes, recent astronomical studies pin-point the exact dates) people started identifying these as mythology more than History !
do u know there is a great controversy whether Jesus was born on 1 AD or 4 AD (So the farther back u go, the more blurred the details become)
But that does not take away the historicity of Ramayan or Mahabharat!
--------------------------- In fact there is more historical proof of Ram then there is of Prophet Abraham actually ever visiting Mecca to make the Kabbah (the VERY BASIS of haj) or for the fact that Adam and Eve ever lived or Muhammed went on a donkey to al aqsa
