A series of lava tubes formed, which you can now access and visit. (ocean-retreat.com)
You can easily spend an entire day here, hiking the trails, walking through lava tubes and feeling the power of nature's primordial forces at work. (luxuryretreats.com)
Here waves channel into lava tubes, and a spray of water pops up every 30 seconds or so. (thisismyhappiness.com)