Just over an hours drive south of Cairns. Head to Gordonvale, then up the Gillies Highway to the Atherton Tablelands. Turn left at the Lake Eacham turnoff, go into the National Park, then turn left at the park exit at Eacham Close. Then follow the signs from there.
You can also come from the Kuranda Range, or from Innisfail up the Palmerston Highway, or from Port Douglas up the Rex Range.