Where is Nibbana
"Is there a place, Nagasena, where nibbāna is stored up?"
"No there is not, yet it does exist. As there is no place where fire is stored up yet it may be produced by rubbing two dry sticks together."
"But is there any place on which a man might stand and realise nibbāna?"
"Yes there is; virtue is the place; standing on that, and with reasoning, wherever he might be, whether in the land of the Scythians or the Bactrians, whether in China or Tibet, in Kashmir or Gandhara, on a mountain top or in the highest heavens; the one who practises rightly realises nibbāna."
"Very good, Nagasena, you have taught about nibbāna, you have explained about the realisation of Nibbāna, you have praised the qualities of virtue, shown the right way of practice, raised aloft the banner of the Dhamma, established the Dhamma as a leading principle, not barren nor without fruit are the efforts of those with right aims!"
The Milinda Pañha was written over two thousand years ago, not very long after the time of the Buddha. Venerable Nagasena was reputed to be an Arahant, though I suppose that Milinda (Menander), being a Bactrian Greek king, was a non-Buddhist from birth. It is apparent from the range of his questions that he had a thorough knowledge of Buddhist teachings. Though the dialogues probably did take place — it may not have been in the form that we now have. The Milinda Pañha could have been compiled by a Buddhist scholar to please the Greek king, perhaps being based on conversations in the Greek king's court. Whatever its origin may be, it is included in the Pali Canon, and is regarded by Theravadins as a masterly exposition of the Buddha Dhamma.