Although I think most people associate Buddhism with India, it has also historically had a strong presence in China, and it is because of China that The Diamond Sutra ended up on my reading list. When I picked it up, the only thing I knew about it was that a copy of it was the oldest existing printed book. The information at the front informed me that it was a Buddhist text, and that it was going to tell me about enlightenment. With that, I went into one of the shortest books I've read in a very long time.
The title translates from Sanskrit to mean The Song Celestial, and the original was a poem or song featuring a discussion between Prince Arjun and an entity called Krishna, which is a deific being. It has been cited as influential and/or inspirational by many who study or come from India, so I decided a few years ago to add it to my reading list, and am finally getting around to it. One of my goals for some time now has been to familiarize myself more with the culture and history of this region, as it is not something I have previously studied extensively, and reading this poem seemed a better place to start than with the entirety of the Mahabharata.