New Zealand's rarest stamp, dating from 1903, has been presented to Te Papa on long-term loan from New Zealand Post.
The stamp, which was incorrectly printed to show Lake Taupo and Mount Ruapehu upside down, is the only known survivor of 80 incorrectly printed stamps.
The image was originally printed in 1898 as part of a 14-stamp pictorial issue of New Zealand scenes.
In the 1903 re-issue, a single sheet of 80 Lake Taupo stamps was incorrectly printed when the sheet was passed through the printing press for the second stage the wrong way around.
The stamp is known as the "four-penny Lake Taupo Invert".
The error was only discovered in 1930 when a farmer in England came across the stamp while searching through his childhood album for stamps to sell for cash during the Great Depression.
A year later it fetched £161 at an auction in London.
It was later sold to the Marquis De Rosny and did not reappear for sale until 1980 when it was sold to an American buyer for 110,500 francs.
In 1998, it was purchased by New Zealand Post for a record $125,000 to coincide with a centenary commemoration reprint of the 1898 pictorial issue.
The stamp was not likely to be sold, but if it were, it could fetch up to $300,000, New Zealand Post said.
It will form part of an existing collection representing the 170 years history of the New Zealand Post Group at Te Papa.
New Zealand Post Group chief executive Brian Roche said the stamp was a national treasure. He was delighted it would go on display at Te Papa.