[1] The castle is situated on a point overlooking Sugarloaf Bay in the Middle Harbour of Sydney.

[1] The mansion was built by Henry Hastings Willis, a former Member and Speaker of the Parliament of New South Wales, as a home for his family.

Access to the castle was originally via rowing boat and a rough bush track.

[3] Innisfallen Castle and Grounds was listed on the New South Wales State Heritage Register on 2 April 1999.

[1] This Wikipedia article was originally based on Innisfallen Castle and Grounds, entry number 00404 in the New South Wales State Heritage Register published by the State of New South Wales (Department of Planning and Environment) 2018 under CC-BY 4.0 licence, accessed on 1 June 2018.