Goa Pindul is a cave located just outside of Yokyakarta but be careful if trying to make this trip on your own. Tourist agencies will book full day guided tours or at least full day transportation in order to make the visit, but when we tried to do this ourselves via buses we ended up hitchiking for multiple legs of the journey. Nevertheless we made it intact. Upon arrival, pick your random barn full of inner tubes, rent one for a few dollars and a local will walk you up to the put in point. The drift through the cave is truly breathtaking, with bats hanging mere feet above you in the dark. If you can go in a small enough group to save the ambiance, you will never forget it.