The woodland garden covers over 140 acres and is home to the National Magnolia Collection. It is recognised as being of outstanding importance by Kew Gardens.
The house is still lived in by the Williams family.
The gardens are open from mid-February to early June when the Spring flowering shrubs are at their best.
The manor of Caerhays belonged to the Arundell family until c1379 when it passed by marraige to the Trevanion family.
John Trevanion, who inherited the estate in 1703, improved the existing house and developed the gardens. In 1767, the male line became extinct and the estate passed to a relation, John Bettesworth whose son adopted the additional name of Trevanion.
In 1807, John Bettesworth Trevanion commissioned John Nash to build a new house in 1807. He might also have asked Humphry Repton for advice although there is no documentary evidence.
With rising debts, Bettesworth-Trevanioni was forced to sell Caerhays to Michael William in 1854.
The woodland gardens were created by John Charles Williams in 1880s who sponsored several plant hunting expeditions. Williams funded many of George Forrest’s expeditions to China until Forrest’s death in Tengyueh in China in 1932.
Williams also hybridised many camellias, rhododendrons and daffodils at Caerhays.