A small castle way up high on a small hill. The castle is very well preserved with lots of rooms, tight stairs, cornices. Cool and dark inside, like a real castle. We went on a friday (holiday), and wow, was it crowded with locals. Bus after bus, cars, packed the tight road up, people everywhere. Total pandemonium. No place to sit and enjoy the castle, kids, moms everywhere. Folks picnic on side of road, under trees, on steps wherever. Excellent WC inside, south end, well marked. Views of valley and local mountains are quite nice (cannot see the river, dam, though). Funicular is right beside it, 8JD pp, a bit expensive to see basically not much for a 30min ride.
Parking is free, but finding it is luck, and courage. The walk up is non trivial. Show your Jordan Pass at gate, before security (all bags x-ray). Road trip there is challenging, tight roads, circles, winding hills, through the dense town of Ajloun where folks stop wherever they want.
3 stars cause it's a lot of work to get there, and then, it's too crowded to enjoy any time there. 10JD entry is a bit steep for all that.