The Heligan estate (//; Cornish: Helygen, meaning willow tree) was the ancestral home of the Tremayne family near Mevagissey in Cornwall, England. Purchased by Sampson Tremayne in 1659, the present house was built in 1692 and extended in the early 19th century. The family let the house after World War I, and by the end of World War II the house and gardens had fallen into disrepair. The house and outbuilding were converted into flats in the 1970s and the garden was considered lost, but it was rescued during a televised project in 1996. The Lost Gardens of Heligan are now open to the public as a tourist attraction.
Originally owned by the Heligans, the estate was bought by Sampson Tremayne in 1659. Heligan House was built by William Tremayne in 1603 in Jacobean style, but only the basement of that house remains. The house was substantially rebuilt in 1692 by Sir John Tremayne (1647–1694) in William and Mary style  and extended in 1810 and 1830. Unusually for Cornwall, the house is built of brick. Set at the top of a hill overlooking Mevagissey, the gardens are found along the hills above and below the house.
The Tremayne family remained at the house until World War I, at which point the house was let out. The tenants were unable to keep up maintenance of the estate and by the end of World War II, maintenance of the house and gardens slipped into decline. The house was divided into flats and sold in the 1970s, with the remaining buildings also being converted into accommodation.
The garden remained in the ownership of the Tremayne family, but was not maintained. It was rediscovered and rescued in a televised project in 1996. The Lost Gardens of Heligan are now a major visitor attraction.
Originally developed by Rev. Henry Hawkins Tremayne the gardens include enormous rhododendrons and camellias as well as a series of lakes fed by ram pump. They include Europe's only remaining pineapple pit, and two large sculptures known as the Mud Maid and Giant's Head.
- "Our Timeline". Lost Gardens of Heligan. Retrieved 1 January 2011.
- "The Lost Gardens of Heligan, Mevagissey, St Austell, Cornwall, UK". www.mevagissey.net. Retrieved 12 August 2016.
- Hitchins, Fortescue; Drew, Samuel. The History of Cornwall: From the Earliest Records and Traditions, to the Present Time. Penaluna. p. 240.
- Browse, Philip McMillan. Heligan: Fruit, Flowers and Herbs. Alison Hodge Publishers. pp. 21–22. ISBN 9780906720400.
- inspired; Willis, edited by Philip McMillan Browse, with a foreword by John (2007). Heligan survivors : an introduction to some of the historic plantstock survivors discovered in The Lost Gardens of Heligan. Penzance: Alison Hodge. pp. 4–5. ISBN 978-0-906720-53-0.
- A Genealogical and Heraldic Dictionary of the Landed Gentry of Great Britain 1863, p.1535: Tremayne descent.
- "Introduction | The Lost Gardens of Heligan". heligan.com. Retrieved 12 August 2016.