The 78-sq-km Eurimbula National Park, on the northern side of Round Hill Creek, harbours an unspoilt landscape of dunes, mangroves and eucalyptus forest. You'll also find pristine beaches, hikes at many levels of difficulty, creeks for boating in, with stingrays and other marine life around the mangroves, and splendid, relatively accessible isolation in the Australian bush.
The main access road to Eurimbula is about 10km southwest of Agnes Water; Queensland Parks recommends a high-clearance 4WD for access.
There are basic camping grounds at Eurimbula Creek (limited rainwater), Middle Creek (no water), Bustard Head and Rodds Peninsula (no facilities). Buy a permit from Queensland Parks & Wildlife ahead of time (adult/family per night $6.55/26).