The River Swale loops around the foot of Richmond Castle in a series of small rapids and waterfalls, and the paths along both banks are the town's best walking. Downstream takes you to Easby Abbey (about a mile and a half each way); upstream goes through Hudswell Woods to Round Howe, a glacial mound the locals once believed to be a fairy hill.
The Falls — really a series of stepped rapids rather than a single cataract — are visible from the bridge below the castle and are best after rain. Look out for kingfishers on the quieter stretches and dippers on the rocks at the falls.