The designed landscape was first laid out during the latter half of the 17th century. It was destroyed after the 1745 rising and was redesigned in the mid- 19th century when construction of the new house, begun in 1802, was resumed.
In the mid-16th century, Ewen Cameron, grandson of the 11th Chief (1st Captain of the Clan Cameron), built Tor Castle, on the River Lochy near Fort William. By the mid-17th century Sir Ewen Cameron (1629-1719) had demolished Tor Castle and built a new castle at Achnacarry on the River Arkaig. He was a political figure and a strong advocate of the Jacobite cause and he was knighted by James VII (II) in 1681. His son, John, took part in the 1715 rising and had to flee to France leaving the estate in the hands of his son, Donald, the 19th Chief, known as 'the Gentle Lochiel'. He joined the rising of 1745. Although badly wounded, he managed to escape from the Battle of Culloden and some weeks later briefly entertained Charles Stuart at Achnacarry. Shortly afterwards the castle was sacked and burnt by the Army and it is from contemporary reports that the gardens are first described. Lochiel's 'fine fruit garden, above a mile long, was pulled to pieces and laid waste. A beautiful summerhouse was also set on fire'.
The Gentle Lochiel fled to France and it was his grandson, the 22nd Chief, who regained the forfeited estate at the age of seven by paying a fine of £4,000. A report written by the factor at that time recorded that the policies and farm were all in ruin and that the woodland on the site of Loch Arkaig was a 'mixture of ash, hazel etc. with a few firs'.
In c.1802 James Gillespie Graham was commissioned to build an 'Adam castellated style' house. Before his death in 1832, the walls were built but the house was not finished. It was his son, the 23rd Chief, who completed the house in 1837 and who became the first Cameron to make it his home. Since then, three more generations of Camerons have lived at Achnacarry and, today, it is the residence of the 26th Chief of Clan Cameron. It has been lived in continuously except when it was taken over as a Commando training camp during World War II; a disastrous fire during the occupation destroyed much of the woodland. The present Chief has been particularly instrumental in improving the gardens.