Whitehall (Flagler Museum)

Standard Oil co-founder Henry Flagler, one of the most influential developers of Florida as a tourist destination, built this Beaux-Arts mansion in 1902 for his third wife, Mary Lily Kenan, hiring the architecture firm Carrere and Hastings. Flagler died in the house in May 1913 at age 83, after a fall down its marble staircase; Mary Lily inherited his fortune, remarried, and died only four years later, in 1917, under circumstances contemporaries called suspicious. Night watchmen and staff have long reported footsteps echoing through the halls, a suited figure that vanishes when approached, silverware rearranged, flickering lights, and porcelain that falls and shatters with no one nearby — though the museum itself maintains there's nothing to it beyond the Gilded Age drama of the decor.