Amsterdam has decided to cut down the 170-year-old chestnut tree that Anne Frank mentioned in her diary while she was in hiding during the Nazi occupation of Holland.

Anne Frank is shown writing in her diary in this April 1941 image. During the 25 months she spent in hiding, she looked at the chestnut tree with longing. Anne Frank is shown writing in her diary in this April 1941 image. During the 25 months she spent in hiding, she looked at the chestnut tree with longing.
(Anne Frank Foundation/Associated Press)
The tree is being attacked by an aggressive fungus and a moth called the horse chestnut leaf miner that has weakened it.

In The Diary of Anne Frank, the Jewish teenager looks at the tree through an attic window of the apartment, concealed in her father's factory, where she and her family hid from the Germans for more than two years.

The factory and apartment where they hid, on Amsterdam's Prinsengracht canal, is preserved as a tribute to Anne Frank and to her book, which has been read by 25 million people worldwide.

"Nearly every morning I go to the attic to blow the stuffy air out of my lungs," Anne wrote on Feb. 23, 1944. "From my favourite spot on the floor I look up at the blue sky and the bare chestnut tree, on whose branches little raindrops shine, appearing like silver, and at the seagulls and other birds as they glide on the wind...

"As long as this exists, I thought, and I may live to see it, this sunshine, the cloudless skies, while this lasts I cannot be unhappy."

The tree was in an inner courtyard and one of the few green living things visible at a time when windows had to be blacked out to prevent neighbours seeing people moving through the apartment.

The chestnut tree, believed to be one of the oldest chestnuts in the city, has been deteriorating for several years.

View of the attic window, left, where Anne Frank looked at the chestnut tree, right, in the courtyard behind the canal-side warehouse, now turned museum, in Amsterdam. View of the attic window, left, where Anne Frank looked at the chestnut tree, right, in the courtyard behind the canal-side warehouse, now turned museum, in Amsterdam.
(Peter Dejong/Associated Press)
"It's very sad, but the decision has been taken," said Patricia Bosboom, spokeswoman for the Anne Frank House museum.

Anne Frank died of typhus in the Bergen-Belsen concentration camp in March 1945.

The museum said grafts have been taken from the tree and a new sapling will be planted in the same courtyard once the old tree has been cut down.