Belvedere Castle was once an open-air structure, with no doors or windows. This changed in 1919 when the United States Weather Bureau moved the Central Park Observatory to the castle. Until that time, weather measurements were taken from the Arsenal at Fifth Avenue and 64th Street where Dr. Daniel Draper founded a meteorological observatory in 1869. The Weather Bureau took over the operation in 1911, and moved it here eight years later, enclosing the castle and altering the turret’s shape to accommodate their scientific instruments.
