The rugged Jonkershoek Mountains, which form part of the Boland Mountains, are ideal for hiking enthusiasts. The Eerste, Berg, Lourens and Riviersonderend rivers all start high in these mountains, although only the Eerste River actually flows through the Jonkershoek valley. The area is also rich in animal and plant life, with over 1 100 plant species and a variety of small mammals, birds and reptiles. Hikers should be on the lookout for berg adders, puff adders, boomslang and Cape cobras.
The reserve is about 9 800 hectares, while Assegaaibosch is about 204 hectares. The smaller reserve is home to the historical Assegaaibosch farmstead, a national monument built in 1790.
Jonkershoek is hot in summer, and cold and wet in winter. Visitors in the colder months may even see snow dusting the higher mountain peaks. Hikers should note that weather conditions can change rapidly.