Mary Pope Osborne

Eight-year-old Jack and his younger sister Annie use the magic treehouse to travel back to the Middle Ages, where they explore a castle and are helped by a mysterious knight.

Jack and Annie travel 500 years back in time to Florence, Italy, and spend a day helping Leonardo da Vinci in the hope of learning another secret of happiness.

Jack and Annie know all about Ben Franklin. He was a Founding Father, a journalist, and a famous inventor! When the magic tree house whisks them back to meet the man himself, they're not sure what their mission is. But Ben Franklin has a mission of his own. Intrigued by Jack and Annie, he's curious to learn more about where they came from. And very curious about their tree house...--Amazon.com.

The magic tree house is back with a message from Morgan le Fay telling Jack and Annie to seek out "The Gray Ghost" and listen to her story, and immediately they are whisked away to Nepal where they meet Tenzin, a climber who has recently lost his family, and who takes them up the mountain to meet a snow leopard and renew himself.

Eight-year-old Jack, his seven-year-old sister, Annie, and Peanut the mouse ride in a tree house to the Amazon rain forests, where they encounter giant ants, flesh-eating piranhas, hungry crocodiles, and wild jaguars.

The magic tree house whisks Jack and Annie to Washington D.C. in the 1860s where they meet Abraham Lincoln and collect a feather that will help break a magic spell.

"When the magic tree house returns it whisks Jack and Annie away to the Galapagos Islands where they become World Turtle Experts and must save a tortoise in danger of an erupting volcano"-- Provided by publisher.

Their magic tree house takes Jack and Annie deep into the sea, where they meet up with dolphins, sharks, and octopi as they search for the answer to an ancient riddle.

The magic tree house transports Jack and Annie to the deck of the Titanic to find a mysterious gift that will free a small dog from a magic spell.

The magic tree house takes Jack and his sister Annie to the Great Plains where they learn about the life of the Lakota Indians.