For over a century, the photographers of National Geographic have brought the Earth in all its splendor into the world’s living rooms with their innovative techniques and intrepid spirit. In celebration of its 125th anniversary, the National Geographic Society has paired with TASCHEN to assemble a three-volume, 1,500-page book, gathering hundreds of the magazine’s most iconic images of nature and culture into one collection. Now, Christie’s is offering high-quality, limited-edition prints of 125 of the book’s stunning images in this unique online-only sale — as well as one of only five copies of the book specially signed by 43 of its featured photographers (president Barack Obama will be gifted one of the other four). Now is the time to own a piece of photographic history.