He says at 1-3-9 that he searched for the information and then wrote the history.
When Seeta was abandoned by Rama, she came to Valmiki’s hermitage.
It is 820 feet tall, has three branches and it glitters like gold, when seen from the sky.
Does this discovery not prove the Ramayana, authored by Valmiki, as true history?
Because he wrote history after gathering information from Hanuman, Seeta, Rama etc. Nala intelligently filled up the gaps in that row, with wood and made a temporary bridge.