The Sydney Town Hall Grand Organ is a large pipe organ built by English firm William Hill & Son in 1890. It is located in the Centenial Hall of Sydney Town Hall in Sydney, New South Wales. Australia.

When it was installed in 1890, Sydney Town Hall's Grand Organ was the larges in the world and described ad the 'finest organ ever built by an English organ builder'. It contains one of only two full-length 64' organ stops in the world (the Contra-Trombone in the pedal) and is the only one working. The other 64' stop is the Diaphone-Dulzian in the Right Stage chamber (Pedal Right division) of the Boardwalk Hall Auditorium Organ at Boardwalk Hall in Atlantic City, New Jersey, United States. 

Source http://goo.gl/ra8xEN