The eruption of Anak Krakatau last week reminded me of the great landscapes and habitats for world building that volcanoes create. Earthsky.org had some beautiful video of the eruptions. https://earthsky.org/earth/anak-krakatau-volcano-eruption-april-2020
I took a trip to Arizona a couple of years ago, presumably to help a friend of mine with research for a book she was writing, but the landscape there inspired an entire alien culture for my third book (delayed release due to you-know-what).
Lava tubes are among my favorite world building choices. The tubes are created when the edges and top of a lava flow cool and crust over, leaving a channel of flowing lava in the center. They create amazing caves with strong, solid walls and ceilings, sometimes miles in length. Great habitats! Plus, the rumblings of earthquakes and the threat of a volcanic eruption upsetting everyone’s plans creates a great sub-conflict.
The longest and deepest lava tube in the world is Kazumura Cave on the eastern slope of Kīlauea on the island of Hawai’i, surveyed at 40.7 miles (65.5 km) long and 3,614 feet (1,102 m). Like any other cave, lava tubes may host underground sources of fresh water, lending another ray of hope to the possibility of finding life on other volcanicly active planets, even those that may not have surface water. (Photo from Wikiwand).
And lest you think that cave homes would have to be dark, damp, and forbidding, check out the luxury Beckham Cave Lodge with all the amenities in Parthenon, Arkansas (www.beckhamcave.com).
Or, what about a whole community of bubble homes?
I can’t vouch for this particular community in Japan (www.japantoday.com) was built, but a similar construction here in the U.S. is done by inflating a fabric “bladder,” basically a big, strong balloon, and spraying a type of quick crete on the inside. Once that hardens, another layer is applied to the exterior, and voila—you have the exterior of a house. These are quick—ready to finish out in a matter of days. You can add more space with more bubbles, and they have the added advantage of being fire and storm resistant.
Or maybe something like these in Holland for areas that flood often (photo from buzznick.com)?
So what kind of exotic life space will your beings develop?