I'm just curious about the origin what they're called I paid $30 for the piece of driftwood fit very nicely in my BioCube and I was a little reluctant to pay $15 for the Cave Rock because I just don't think it really works but I bought nonetheless I'm a fish saying junkie and I see something cool and I have to buy it and I'm like why did I buy it I'm going to do an open-top so I love the fact that the Driftwood sticks out of the top