I really loved this place. So much to explore in ways that aren't usual for a national park. And the sudden change from farmland to lava beds is startlingly fast. The rangers at the visitor center are especially helpful for both advice on what to explore and what to bring with you.
It's a really good idea to bring your own bike helmet and what lights you can, you'll need two on each of you and remember that your cell phone can count as a backup. But it's also good to have a backpack and a head lamp to leave your hands free for the difficult parts of the paths.
But if you forget everything the Visitor Center can supply you. And the darkness in the stone is pretty breathtaking.
We also managed to lock our keys on the car, and the law enforcement rangers were good enough and kind enough to break gently into it car and get us back on our way. I'm really grateful they could help.