One of the great things about art is that it’s always open to interpretation. You can pore over your favorite painting over and over again and still discover a new cryptic symbol or hidden detail.

Some of the most famous artists in the world intentionally put secret messages in their paintings, whether to subvert authority, challenge audiences, or reveal something about themselves.

Hundreds of years later, thanks to advancements in technology, many of these secret messages are first being discovered. So read on to learn 10 mind-blowing secrets hidden in the most famous works of art.

God’s brainy entourage
There’s a scientific secret hiding in one of the most famous paintings of all time. It resides on the ceiling of the Sistine Chapel, painted by Michelangelo, as God gives Adam the first spark of life. The flowing reddish-brown cloak behind God and the angels is the exact same shape as a human brain.

Researchers have even been able to pick out certain parts, like the vertebral artery (represented by the angel right beneath God and his green scarf) and the pituitary gland. There are multiple theories as to why Michelangelo might have done this; one suggests that the brain represents God imparting divine knowledge to Adam.

A more popular theory, however, suggests that Michelangelo painted the brain in a covert protest of the church’s rejection of science. Secret messages in these 12 company logos are almost as shocking as these Sistine Chapel theories.

How very un-angelic
An angel with attitude can also be spotted on the Sistine Chapel ceiling. The Pope who commissioned the work, Pope Julius II, was widely disliked—including by Michelangelo. The artist decided to take a subtle dig at his unpopular patron by painting the prophet Zechariah to look like him.

One of the angels behind Zechariah/Julius is making an old-fashioned snarky hand gesture called “the fig” in his direction (for those of you interested in bringing it back, it looks a lot like “got your nose”). The artists behind the funniest famous paintings ever were clearly having a little fun, too.

The man in the mirror
Fifteenth-century artist Jan van Eyck couldn’t resist sneaking himself into his famous Arnolfini Portrait. In a not-so-secret act of self-promotion, van Eyck wrote “Jan van Eyck was here 1434” on the wall in Latin behind the two figures. But far less noticeable are the other two figures in this painting.

If you take a close look at the mirror on the wall, you’ll be able to spot two people who appear to be standing about where the “viewer” of this scene would be. It is widely believed that the one with his hand raised is supposed to be van Eyck.

Mona Lisa’s canvas-mate
Though the popular treasure hunt thriller The Da Vinci Code is speculative to say the least, Leonardo da Vinci did hide some secrets in his most famous works. Namely, the Mona Lisa, a famous painting among famous paintings, the Louvre museum’s most visited work.

This enigmatic lady actually has the artist’s initials, LV, painted in her right eye, but they’re microscopically small. Even more surprising, in 2015, a French scientist using reflective light technology claimed to have found another portrait of a woman underneath the image we see today.

The consensus is that this was da Vinci’s “first draft,” and that he painted over it to create his masterpiece. In addition to her hidden messages, did you know that the Mona Lisa is also one of the most expensive things to ever be stolen?

Botticelli the botanist
The artist best known for The Birth of Venus, it turns out, had quite the affinity for plants. In another of his famous paintings, Primavera, researchers have found as many as 500 different plant species, all painted with enough scientific accuracy to make them recognizable.

The Last Supper’s musical bread
Da Vinci’s other world-renowned m

asterpiece, The Last Supper, has been said to hint at everything from Christ’s later years to the date the world will end. But one far less heavy theory might just have some merit to it. Italian musician Giovanni Maria Pala discovered what could very well be a little musical melody written into the painting.

If you draw the five lines of the staff across the painting, the apostles’ hands and the loaves of bread on the table are in the positions of music notes. Read from right to left (the way da Vinci wrote), these music notes form a mini 40-second hymn-like melody.

Going strapless = unacceptable
This woman rocking an LBD, immortalized as “Madame X,” is actually Virginie Amélie Avegno Gautreau, a Parisian socialite. The 19th century artist Jon Singer Sargent decided to paint a portrait of her, hoping that it would get his name out there. It did…but for all the wrong reasons.

In the original portrait, the right strap of Madame Gautreau’s dress fell down her shoulder, and the high-society viewers of the portrait found this mini wardrobe malfunction to be absolutely scandalous. Sargent re-painted the strap to be in its proper place, but the backlash continued and he ended up leaving Paris altogether.

However, he was able to sell the piece to the Metropolitan Museum of Art, so things worked out all right for him. For more shock and awe, you’ll want to visit these 8 crazy museums you won’t believe are real.

There’s a skull skulking in this room…
See if you can find the skull hidden in The Ambassadors by Hans Holbein the Younger. Nope, you won’t need a magnifying glass for this one—it’s actually pretty big. Don’t believe me?

That beige-and-black diagonal blob at the bottom of the painting becomes a skull if you look at the painting the right way. Take a look from the bottom right or left of the image, and see if the skull comes into focus. These much more modern, but equally fascinating, optical illusions are also mind-boggling.

The other Last Supper?
Vincent Van Gogh, the artist behind the famous paintings The Starry Night and Self portrait, also produced this colorful painted café scene, Café Terrace at Night. It may be more than just a simple depiction of diners, however. There are many clues pointing to this painting being a more modern riff on da Vinci’s Last Supper.

For one thing, Van Gogh was very religious, and his father was a minister. The image also features exactly 12 people sitting at the café. They surround a standing, long-haired figure who just so happens to be standing in front of a cross-like shape on the window. Not every painting is so rare—Bob Ross made three copies of each of his paintings.

Drowning your sorrows in wine was never so artsy
Caravaggio’s portrait of Bacchus, the Roman god of wine, is another work of art hiding a miniature self-portrait by the artist. In 1922, an art restorer was cleaning up the canvas of this 1595 work. With the centuries’ worth of dirt buildup gone, a hidden portrait became visible.

In the glass wine jug in the bottom left-hand corner, an itty-bitty Caravaggio sits in the tiny light reflection on the surface of the wine. There are hidden messages in other art forms, too, like these 14 hidden messages in your favorite movies.

Writter : Meghan Jones