Ryoan-ji is a Buddhist temple famous for its Zen rock garden, built in the 15th century. Although the rock garden may be the main attraction, the temple grounds are beautiful, especially during the cherry blossom time or during Fall.
After purchasing your ticket, you'll follow a path along the grounds. There's a lake with a small boat and a little island with a small shrine. There are many cherry trees with beautiful blossoms in spring. There is also different kinds of moss covering the trees and ground.
The path leads up to the main temple which contains the rock garden. The garden is composed of raked gravel and fifteen rocks. From every angle except one, only fourteen rocks can be seen. You are allowed to sit in front of the garden and contemplate to your heart's content. The Buddhists want you to come to your own conclusion about the garden and what it means to you. They don't tell you what you should see.
Ryoan-ji is another popular temple that is best visited in the morning, before the crowds hit. It opens at 9am and this is when you'll find the fewest people. Having less people there allows you the best atmosphere for meditation or deep thought.
Although staring at rocks may not sound like a great time, if you're in the right mental state then it can be an exhilarating experience. The wonderfully landscaped grounds can help bring this about. Be sure to come here with a calm mind.