Ajlun is a small town and the main sights — the castle and the nature reserve — are a few kilometres apart. The castle sits on a hilltop about 2 km from the town centre; the nature reserve visitor centre is a further 3–4 km to the south-west.
Taxis are the easiest option for moving between the town, castle, and reserve. Drivers are accustomed to tourists and will quote a waiting rate if you want them to stay while you visit. Agree on the price before getting in.
On foot between the castle and town is possible but steep. The castle road climbs sharply from the valley floor and is not particularly pleasant to walk along. A better plan is to take a taxi up and walk down.
Within the nature reserve, the RSCN trails are well marked and easy to follow. You do not need a guide for the shorter routes, though one is required for some of the longer trails (ask at the visitor centre). Trail maps are available at the entrance.
There is no public bus between the town centre and the castle; minibuses from Jerash drop off in town, not at the castle.