Everyone crossed the entrance that led to the volcanic mesa's roof. Inside, It was a wide, nearly circular arena of 600 meters in diameter, surrounded by 20 meters tall rocky walls. Most of its surface was perforated. There were a lava lake 100 meters below them, shooting magma streams and exhaling black gasses.
They stepped on a natural bridge, which led to various rocky cornices and platforms distributed around the edges. Platinized-lilac walls showed among the eroded rocks, covered by hexagonal patterns and pasted rocks that time couldn't remove yet.
Various devices and rooms of hexagonal doors hanged on the walls on the right side, connecting to the main platform through artificial bridges. They reminded John of the volcanic moon of Jupiter, Io. Research facilities and outposts were
