Looks like this a wood burning fire pit made of a brick or stone. My main reasoning is that it would be difficult to run a gas line through the sand. If you wanted a gas fire pit that could sit on a similar surface, a portable fire pit like this one could be an option.

Nope, this is a lp gas fire pit with ceramic logs.... It is difficult to find fire wood in the Caribbean. We ran a conduit with the gas line within.