'Null Island' is a geographers' joke, but a real buoy sits at its coordinates

Null Island is the tongue-in-cheek name for 0° latitude, 0° longitude, a point in the Gulf of Guinea with no land at all. Because mapping software often defaults to (0,0) when an address fails to geocode, real records get silently mislabeled there — and an actual NOAA weather buoy now floats at the spot, giving the fictional island a genuine landmark.

— Atlas Obscura, Null Island Is One of the Most Visited Places on Earth. Too Bad It Doesn't Exist — 2018