The garden takes its name from the statue of Hercules placed in 1743 on top of a small hill just outside the south wall, from where there is a splendid view down into the garden below.
A 'Chinese' style bridge crosses one of the ponds.
The slopes on either side of the ponds are planted with widely spaced vertical lines of fruit trees, known locally as 'breaks'. The garden also incorporates herbaceous borders and a vegetable plot.
In 1924 elaborate gates were hung to celebrate the silver wedding of the 8th Duke and his wife.
But by the end of the Second World War the garden had fallen into decline and all the greenhouses were in a state of dilapidation. It was the late 10th Duke of Atholl (1931-1996), known as 'Wee Iain' who initiated the restoration. He died in 1996, the year the restored garden was opened to the public, and is commemorated in an inscribed stone as well as in the statues of a shepherd and a shepherdess beside MacGregor's Folly.