I'm considering making a novel about something weird that really happened sort of: an island that was on every map of the world, but never really existed.
The real deal is called a Phantom Island, and the one that snagged my attention is called Sandy Island of New Caledonia. TL;DR version: we thought it was there as it was on a lot of maps, it ended up in the OpenSource Global Coastline Vector, NASA used it to adjust focus on the satellite cameras, it ended up on Google Maps and everything else because it looked different, and someone eventually went there for research and... "Where'd the island go???"
Now for the novel, the theory is that it's some kind of time-travel research lab that got zapped to our time, and is hidden by tech that messes up any way to find it: to hide it from satellite cameras, it makes them look 30 miles south into open ocean; it messes up satellite phones and GPS, so no communication and you think you're far to far north; and some other things to mess up any tech from outside that wants in.
I'm still working on the plot, but does anyone have any ideas as to what sort of modern tech could possibly be developed to serve these roles in concealing the island? And have any other ideas? The idea is to make it make sense that nobody can find the island/laboratory, but people can leave there, and come back if they know what they're looking for. Its a time manipulation research lab from sometime in the future, stranded in today's world, so although I'd love it if we used "possible tech" that we are working on and may develop, it is a future-themed sci-fi so go nuts.