Kilauea Caldera. As recently as the late 1800's, the bottom was twice as deep as it is today (about 500 feet today) and one could see lakes and fountains of molten lava churning. It solidified roughly in the configuration seen today in about 1905. However, there has been occasional seepage of lava through fissures, forming lava flows as recently as the 1970's. The hole you see in the distance (with the large steam plume) is Halema'uma'u, the central crater of the caldera. As recently as 1924, it contained a molten lava lake. Now, the rock is thought to be solid down to a depth of about 2 miles below the surface.

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