The Amstel House in New Castle, Delaware, is most famously haunted by the "Lady in Blue," a mysterious spirit frequently featured on local ghost tours. The house's long and notable history has led to other reported paranormal activity as well. The legend of the Lady in Blue is the most well-known ghost story associated with the Amstel House. Guides with the New Castle Historical Society often tell the tale of the "Woman in Blue" during the seasonal Hauntings in History walking tours. The spirit's identity is not definitively known, and tour guides offer several potential historical women who may be the ghost. The Lady in Blue is said to appear in the house, where she has been seen by residents and visitors.