The What Do We Know About? series explores the mysterious, the unknown, and the unexplained. Why was Sarah Winchester's puzzling mansion built with so many mysterious features? And is it truly haunted?

In 1884, Sarah Winchester began building a large mansion in Santa Clara County, California. Under Sarah's direction, the house rose to be seven stories high and filled with mysterious features, including stairs that lead to nowhere and windows that look into other interior rooms. The house is more than just oddly designed, however: Many people believe that it is haunted. What made the heiress to the Winchester rifle fortune, an independent woman in many ways ahead of her time, create such an unusual house? Is it really filled with ghosts and spirit energy? Find out more in this nonfiction title about one of America's most famously unexplainable and possibly haunted houses.