Sandstone pagoda country north-east of Mudgee, where weathered rock formations rise over the woodland along the gap. The Castle Rocks walking track leads out to a lookout among the pagodas, and the Moolarben picnic area handles the barbecue end of a visit. The reserve is best known to birdwatchers: 164 species have been recorded here, the rare regent honeyeater among them. It is also an important place for the Wiradjuri people.