The Winchester Mystery House is a sprawling mansion in San Jose, California, known for its unique architectural features and rumored paranormal activity. Built by Sarah Winchester, widow of firearm magnate William Wirt Winchester, the house is said to have been continuously under construction for 38 years, with staircases leading to nowhere, doors opening to walls, and secret passageways throughout. The house has become a popular tourist attraction, drawing visitors from around the world to explore its mysterious and eccentric design.