One of the places that might have a scene in the Vallar sequel is Olympus Mons, so I went on a tour of the place recently.
Olympus Mons is the largest volcano on Mars, but also the largest known volcano in the solar system.
It’s 25 kilometers high (82,000 feet) and has a diameter of more than 500 kilometers.
The entire chain of Hawaiian Islands would fit inside Olympus Mons.
The lava flows on the Martian surface are observed to be much longer, probably a result of higher eruption rates and lower surface gravity.
Another reason why the volcanoes on Mars are so massive is because the crust on Mars doesn't move the way it does on Earth. On Mars, the crust remains stationary and the lava piles up in one, very large volcano.
There are very few craters on its slopes, indicating that it is geologically very young. Olympus Mons is presumed to be less than 100 million years old.
The name Olympus means the house of Zeus.
Interesting possibilities for scenes.
There could be many empty lava tubes making for interesting passages and discoveries.
People could be living inside of it.
It could be a launching site to get off the planet.
Although not mentioned in the first book, Captain Bret Yargar has camped there with his family.
I also see some possibilities for using it as some sort of symbolic meaning, but I don’t want to give anything away.