Doro Gorge is an inland river gorge in the mountains west of Kumano, usually visited by boat. The water cuts between steep rock walls and forested slopes, giving a very different view of the Kii Peninsula from the Pacific coast.
It takes more planning than the sights near Kumanoshi Station, but it is worth considering if you have a car or are building a wider Kumano itinerary around river valleys and pilgrimage paths.