Castlewellan Forest Park covers about 460 hectares of woodland around a 40-hectare lake on the edge of Castlewellan, a few miles north of Newcastle. Its heart is the Castlewellan Arboretum and Annesley Garden, begun in 1740 and greatly expanded by the 5th Earl Annesley; it has been called one of the most remarkable tree collections in Europe, with giant sequoias planted in the 1850s and the original 'Castlewellan Gold' cypress. There is also a large Peace Maze.
The Scottish Baronial castle is a Christian conference centre and is not open to visitors. Unlike Tollymore, the park allows mountain biking.