Winchester Mystery House

The Winchester Mystery House or Winchester Mansion is a Queen Anne Victorian style mansion in San Jose, California United States of America. 
History.
The house was built by Sarah Winchester after her family had passed away. A spiritual medium convinced Sarah that the deaths in her family were part of a karma type curse on her that could only be satisfied by constantly building a labyrinthian mansion according to the wishes of the ghosts of the people killed by Winchester rifles. The result is a higgeldy-piggeldy four-story maze of rooms and corridors with staircases leading to ceilings, doors leading to 10-20ft/ 3-6m drops to the ground outside or the floor level directly below, windows between rooms and other crazy anomalies. 
Structure.
The main stairs are far shallower than usual to accommodate Sarah's arthritis, and there's three elevators in the house too! There's also cryptic symbology throughout the Winchester Mansion, like repetition of the motif 13. 
Cost.
The house cost $5,500,000 to build ( close to $30,000,000 in today's money) and if it was built nowadays, would not meet any building codes.