There are striking similarities in the teachings of Zen buddhism and the advaita teachings of Sri Ramana Maharshi. I found a beautiful story that talks about the practice of zazen and I was immediately struck with not only the teachings being exactly what self-enquiry is, but also the use of the metaphor (that of the moon and the bucket with its reflection in it) being exactly the same. Talking about the moon, I found another story, about a monk Ryokan and the thief that couldn't steal the moon. This one always makes me teary eyed.