The Mount Washington Hotel was designed by Charles Alling Gifford and built between 1900-1902. It was declared a National Historic Landmark in 1986. It is sometimes referred to as the Stickney Mansion, after its founder, Joseph Stickney.
The building is allegedly haunted by Carolyn Stickney, wife of Joseph, whose ghost has been sighted there. Other visual effects include a white mist.
Audible phenomena include knocks on doors and a baby crying. Some have been captured on audio.
Pictured left is the Mount Washington Hotel courtesy of rickpilot_2000.