The building in Egypt is a replacement of the Great Library of Alexandria established in 250BC which later burnt down.
The Duchess sat with youngsters painting in the Children’s Library before she read Michael Rosen’s ‘We’re Going on a Bear Hunt’ to a group.
Asked to name their favourite books the children named Harry Potter, Danny Champion of the World and Aladdin.
Camilla replied: "Aladdin? It would be nice if you had a lamp and our wishes all come true."
After one of the children handed Camilla a paper flower, she said: "It smells delicious. You can wear it in your hair, very pretty."
Camilla and Charles were shown exhibits including Romam mosaics, statues and Arab and Islamic manuscripts.
Camilla said: "Absolutely marvellous. So much to see could spend all day here."
The couple, who went different directions through the building, were serenaded by violinsts in the library’s Great Reading Room.
The library rebuilt in 2002 has space eight million books, with the main reading room covering 20,000 square metres.
The Manuscripts Centre boasts ancient Arab and Islamic texts.
The ancient Great Library of Alexandria burnt down around 1,750 years ago.
It was one of the largest and most significant libraries of the ancient world.