A good view of such a lava tube is shown below.

There is a lava tube, just one, under the site.

Or else this was one hell of a lava tube.

They set up a camp back out of the weather in an old lava tube.

The cave is an excellent example of a lava tube.

The major caves of the Horse system are lava tubes.

You can peer into a lava tube with its own ecosystem.

They emerged from the lava tube, into a dazzling morning.

One such lava tube was discovered in early 2009.

It is also the largest lava tube in Jeju island.