While allowing for an unprecedented view of our planet, Google Earth has observed a number of locations around the world that were deemed too secret to share with users.
Rather than the crisp overhead view that one normally sees from the service, these sites are presented as blurred or pixelated images.
What is puzzling is that many of the censored sites are seemingly benign places, spawning conspiracy theories that there is more than meets the eye at these locations.
An oil refinery in Hungary, an archipelago in the Atlantic Ocean, and a major city in the Philippines are among the places that Google Earth inexplicably cannot show us.
One particularly bizarre location is a Russian city in Siberia which is rendered as a giant blur by the service, leading many to conclude that something sinister may be afoot there.
Researchers suggest that many of these locations are the sites of secret military installations or research projects and, thus, their home countries have had Google Earth obscure them from view.
This theory is bolstered by the fact that sites like HAARP and an air force base in Utah where weapons tests are conducted are among the American locations on the service's blacklist.
Whatever may be happening at these locations remains open to speculation and debate, but, ironically enough, by virtue of obscuring them from view on Google Earth, the 'powers that be' have only really succeeded in creating even greater interest in the mysterious sites.