Ryoanji is probably one of the more famous Buddhist Zen rock gardens around. It is actually very close to Kinkaku-ji which is just one bus stop away or you can also walk your way there if you have the energy. Admission is 500 yen and it’s open from 8am-5pm. It is accessible by Bus no.
To be honest, I kind of expected to feel the zen since it should be a zen rock garden but it was crowded and you can hardly find a place to sit and just appreciate the rock garden. It would probably be a good idea to go there early in the morning. This is not in my top 5 places to visit in Kyoto. You can actually skip it if you have limited time. I wouldn’t really recommend it.