Genghis Khan terrorized Mongolia for more than 20 years, and when he died he was pretty rich. And like many wealthy leaders of his time, Genghis wanted to be buried with all of his stuff. The problem when you are a wealthy monarch, though, is it that once people know or suspect you’ve been buried with all of your stuff, you’re in great danger of being unearthed.

So Genghis Khan’s place of burial was kept secret. How is this possible? Well, the people responsible for his burial made very sure that no bystanders could reveal the location of his tomb. According to the BBC, Genghis was carried to his tomb by an army, which dutifully killed anyone it encountered on the road. And after he was buried, the soldiers trampled his grave site under the hooves of 1,000 horses, which effectively destroyed all the evidence. Some legends even say the soldiers killed the slaves who dug the grave, so they would never reveal the secret.

It seems to have worked. In the 800 years since, expeditions specifically looking for the infamous emperor have consistently failed to find diddly. Although, it’s not as if they had a lot of support from the Mongol people — locally, it’s considered taboo to look for Genghis Khan’s grave. Not because of some stupid legendary curse or something, but because Genghis asked to be buried in secret, so locals think his grave should remain secret.

Today, vampires seem kind of cool and occasionally glittery, but in the ancient past, the idea that a corpse might be able to reanimate and eat the living wasn’t just fiction, it was a very real fear that people had during a time when humans didn’t have a whole lot of control over things like illness and death.

According to History, some of these fears may have stemmed from early people’s inability to comprehend the physical processes of decomposition. Decomposing bodies tend to bloat — we know today that this happens because of a build-up of gases, but in those days it just looked like the corpse was getting fatter. And to add to the horror, sometimes those gasses force blood into the mouth, which kind of does make it look like maybe Bob’s body is getting fat because he’s been feasting on the blood of the living.

Fear that a corpse might reanimate was pretty widespread, and as a result we have a number of “vampire burials” in the archaeological record. These types of burials were usually reserved for people who were believed to be vampires, or at least at risk of becoming vampires after death. The people who buried these individuals made sure to take precautions, like placing sickles around their necks. That way you didn’t need to desecrate the body by actually decapitating it, because the decapitation would only happen when and if the person decided to rise from the dead.

Circles and spirals seem to have had particular significance to the indigenous people of Central and South America. According to Ancient America, the spiral was often used to represent water, possibly because of its association with shelled sea creatures. It’s not super clear, though, why 10 skeletons found at a burial site in the Mexican city of Tlalpan were arranged in a spiral formation with their body parts interlocked.

The grave contained the bodies of at least two women, one man, one child, and an infant. And their arrangement almost suggests intimacy — one body was buried with its head resting on the chest of another, one had its hands under the back of another, and the baby was positioned on top of one of the bodies. The general orientation was in a spiral, as if the group was moving around the center of a wheel. So far, this is the only gravesite known with this particular arrangement of bodies.

The question remains, though, what such a burial might mean. In this part of the world you can’t ever rule out a deliberate killing, but the people could have also been victims of a massive disaster or other deadly event. The arrangement of the bodies and the fact that they come from different age groups makes researchers believe that the burial may have been ritualistic, possibly some kind of representation of the circle of life.

Unsurprisingly, bizarre burials didn’t just happen in the ancient world. Modern people can be pretty quirky, too, even about things that happen after they’re dead and buried. In Timothy Clark Smith’s time, there was an epidemic of taphephobia, which is the totally rational (at the time at least) fear of being buried alive. It was kind of hard to know for sure that a body had truly shuffled off this mortal coil, and there were some stories — horrible, horrible stories — about coffins of exhumed bodies with scratch marks in them, as if the dead person had woken up and tried in vain to escape.

Smith, though, wasn’t satisfied with just one of the usual precautions like installing a bell above his gravesite that he could ring from inside his coffin. His whole tomb was a precaution — he had the bell, but he also had a breathing tube and a staircase, you know, in case he felt able to walk out of his grave after waking up. The most notable precaution was the installation of a window, which was placed six feet above his face so visitors could look down and confirm that he was, in fact, dead.

According to Atlas Obscura, Smith still lies in the same grave, so evidently his fears didn’t amount to anything, which is kind of unfortunate in retrospect. And over the years, the window fogged up, so he’s finally got some privacy, too.

The death of a loved one is always terrible, but there’s something especially awful about losing a child. Parents cope with that kind of grief in a lot of different ways, and it’s not up to us to judge them for it. For one grieving father, though, coping meant going way outside the bounds of what most people would consider.

Rosalia Lombardo was a beautiful child who was only 2-years-old when she died. According to the official website of the Palermo Catacombs, Rosalia’s father was so distraught at her death that he asked a local taxidermist named Alfredo Salafia to make her “live forever.” Salafia accepted the challenge, and Rosalia’s prepared body was placed into a glass coffin in the Palermo Catacombs, which today is a sort of macabre tourist attraction in Italy. (People started putting bodies in the catacombs back in 1599 — the original occupant was a friar named Silvestro da Gubbio, who still watches visitors from his place on the wall.)

Salafia was so successful that years after her death, Rosalia appears to be merely sleeping. Years later, she looks a little less perfect than she did in 1920, and the fact that she’s surrounded by thousands of much less-well preserved corpses kind of spoils the effect anyway. Still, she’s generally regarded as the world’s most “beautiful” or at least most well-preserved mummy. Today, her coffin is filled with nitrogen to keep decomposition at bay.