Winchester Mystery House (San Jose, California)
The magnificently strange mansion was under non-stop construction for 38 years by a wacky widow named Sarah Winchester (who had been married to one of the Winchester Rifle heirs) who was told by a medium that she had to keep continuously building her house or the spirits of those who had been killed by Winchester Rifles would come after her. So… build she did… an incredibly strange house where stairways lead to ceilings, doors open to nowhere, and the number 13 figures very prominently. Great place!