"The magic tree house whisks Jack and Annie away to South America, where they must climb Machu Picchu to save a baby llama"--

"When the magic tree house whisks Jack and Annie back in time, they land in the tallest tree in Yosemite, California where they join nature conservationist, John Muir, and US President Teddy Roosevelt on a historic trip through the woods"--

Their magic tree house takes Annie and Jack to Pompeii just as Vesuvius is about to erupt, and they must find a Roman scroll before everything is covered with burning ash.