I left the description of my Oasis Springs mostly unaltered, but added that it's the best place to meet aliens from the planet Sixam. Because in the history of my save, Oasis Springs is where simkind first made contact with extraterrestrial life. As such, the focus of this world is on astronomy and other sciences, and of course the various kinds of aliens themselves.
https://abload.de/img/oasisspringsthjat.png
Mirage Canyon is the commercial district and still includes the original lounge and fitness studio. I replaced the bar with a library where an alien club regularly gathers, and in-story, this is the place where sims from outside Oasis Springs go to make alien friends. The museum was moved to another part of the world and in its place is now a retail store where sims can buy alien crystals, metals, science potions, etc.
Skyward Palms is a community of aliens and regular sims co-existing peacefully, and the well-known residence of three people who played an integral part in establishing human-alien relations as we know them today: Bobo, the alien scientist turned mayor of Oasis Springs who accidentally crashed his UFO in the outskirts of the town thirty years ago, the now elderly Froufrou who discovered said UFO, fell in love with the alien inside and became his wife, and Professor Magnus Sixam, the first human to travel to the alien planet that he promptly named after himself.
Bedrock Strait features a different kind of sapient alien species also originating from the planet Sixam: the asari, which Mass Effect fans will know from... well, Mass Effect.
https://abload.de/img/13asarijpgpyj9b.jpg
I treat them as aliens in my game even though they're technically only alien-looking spellcasters (or vampires) with additional alien powers that I gave them via cheat. They can be encountered all over my sim world (even one of the Magic Realm's sages is an asari), but Bedrock Strait is exclusive to them. The neighbourhood also features a Sixam-inspired night club and the original Oasis Springs museum turned into a planetarium and gathering place for my astronomy club.
The old military base in what used to be the Desert Bloom Park was built as a home for more Mass Effect characters, human and alien alike, but I never moved them in, so now I'm toying with the idea of turning it into an asari monastery instead, and claiming that this neighbourhood is a part of Bedrock Strait.
Not much to say about Acquisition Butte, it has a huge laboratory for all kinds of scientific endeavours and the swimming pool that was originally in Windenburg, because, well, the desert needs it more than Windenburg.
Last but not least, Parched Prospect is the only neighbourhood of Oasis Springs that doesn't belong to the aliens, at least if we define "aliens" as extraterrestrial beings. Unofficially called the Selvadoradian district, it is inhabited by a family of human archaeologists and otherwise filled with a Selvadorada-inspired restaurant, cantina, museum, and retail store.