If you ever find yourself flying over Coronado Island, it would be very hard to get lost. That's because there's a message in the sand — but you can only read it when you're sky-high.

The dunes along Central Beach have been arranged to spell "Coronado."

This formation is sometimes called "Mando's Dunes," named for local maintenance worker Armando "Mando" Moreno. On Martin Luther King Jr. Day in 1988, a storm washed tons of kelp ashore, and rather than dispose of it, he piled it atop the sand, forming little dunes. As Moreno collected more kelp and seaweed over the following two years, he organized his mounds to spell the city's name and topped them with ice plants.

At first, the sand art wasn't well known because the letters are too large to read from the ground. However, Moreno couldn't hide the message from everyone. US Navy pilots — and maybe eagle-eyed travelers approaching San Diego International Airport — could read the sandy secret.

The message eventually got out to the masses thanks to Google satellites, and now many can see Moreno's creation. Fun fact: Local lore surrounds the dunes, like the rumor that a whale was buried in one of the letters, but that's never been proven.

Despite creating the sand formation, Moreno didn't get to read it until a local pilot took him on a coastal flight in 2011 and he got a bird's eye view of his work.