Ishikiri Hot Spring located in Hotel Seiryu is just amazing. There are just two baths: one large indoor one and a smaller outdoor one but that's all you need thanks to the amazing water. The hot spring here is actually a cold spring that is heated up and recycled into the baths. Heated water is straight up amazing, but in the bath head over to the corner where the fountain is. You'll notice two flows of water into the bath. The larger one is the heated (and maybe diluted) spring water. The smaller one is the straight from the well water. It's much colder and you can tell instantly on your skin that this is a unique spring.
Outside the small bath is great, but the view is absolutely amazing. You can see right were the Daini Hanna road and the Kintetsu Keihanna Line enter tunnels to go under the mountain you are on and head to Nara. It is not just that either, right in front of you is the Kintetsu Nara Line where you can see the Kintetsu and Hanshin trains pass by most of them quite slowly as Ishikiri Station is a stop for all but the fastest trains on the line. In the landscape, Harukas the tallest building is clearly visible along with the Nanba and Umeda centers of Osaka. It's worth just going to Ishikiri Station for the view, but seeing it from a bath makes it all the better. Oh, and I went there on a rainy day and found it to be amazing. I can only guess how beautiful it would be at night or on a clear day.
The hotel itself is older but quite friendly and has that lovely bubble era feel to it. The staff were also very kind and welcoming.
Nearby is a hiking course up over the mountain to Ikoma if you are interested. I went about half the way up and saw the old waterwheel and kanpo 漢方 factory on the way. Billows of cinnamon and ginger smelling mist came out of the factory over the road. The path is steep and I'm still sore a few days later from that short walk. Here's one hiker's route: http://www.yamareco.com/modules/yamareco/detail-383566.html