There’s a secret investor who’s actually building a real underwater city right now. Yep, like something straight out of a sci-fi movie! The plan is to create a livable place deep under the ocean, with air, power, and even fancy tech to make it feel like home. Not much is known about who’s funding it, but it's supposed to be super high-tech and eco-friendly. Scientists are both excited and nervous, since living underwater could mess with marine life if it’s not done carefully.