Towering granite cliffs flank two large granite outcrops, Mount Castle Tower and Mount Stanley—the highest peak on the Many Peaks Range.

Experienced, fit and self-sufficient bushwalkers with skills in bush navigation can explore the park and enjoy panoramic views over the Boyne Valley, Lake Awoonga and Gladstone from the summits. Spectacular wildflower displays can be seen in late winter and spring. There are no formal walking tracks or route markers.

Castle Tower National Park is aptly named to reflect its dominant landscape feature—towering granite cliffs flanked by two large granite outcrops.

Open eucalypt woodland with a shrubby heath understorey covers most of the mountain. The heath contains plants found only locally, such as the Byfield spider grevillea Grevillea venusta. Small areas of montane heath occur on the high peaks. Dry rainforest scrub grows along gullies and creeks. The park is the southern limit of white gum Eucalyptus platyphylla.

Panoramic views over the Boyne Valley and Gladstone can be enjoyed from the summits of Mount Castle Tower and Mount Stanley—the two highest peaks in the park. Mount Castle Tower is 475.5m above sea level and Mount Stanley is 690.9m.