Very easy to get to and worth the trip. This castle is a good one to use as a judge of all other castles you might see while traveling around. Don’t just go to the castle but walk around the outside or maybe up some of the hills behind the castle to get a very different view.
Take the JR right to Himeji. At the station go to the main street and you can see the castle. It is about a 15 minute walk from the station. (Alternatives – take the Sanyo line from Suma, and walk through the shopping arcade to the right of the main street as you face the castle.)