 Its history dates back to 1796 when it was used as the site of the first windmill in the colony, when it was known as Windmill Hill.It is also the site of a number of historical buildings including the historic Sydney Observatory (thus often referred to as Observatory Hill), the Signal Station, the remains of Fort Philip, the National Trust Centre (formerly Fort Street High School) and a rotunda which is used for weddings.A windmill was constructed on the site in 1796 by John Davis, an Irish convict.