When I was a kid I always thought that Timbuktu is an imaginary city because the name sounded a bit funny to me. But it is not, this city is far away in the middle of Africa. This city was very rich and famous in the 12th century (almost 1000 years ago), even before America was found.
In those times it had colorful markets, tall towers and thousands of houses made out of stones and bricks. The city was rich in gold, ivory and jewels. Traders came from all over the world and traded grains, sugar and salt for the gold, ivory and jewels.
Timbuktu was ruled by a very wise and powerful ruler Aksia the Great. The court of King Aksia shone with gold and jewels. Other things that were very popular in Timbuktu were books and music.
What do people mean when they say that some place is as far as Timbuktu? It means very very far away.