Haunted houses, crumbling Transylvanian castles, abandoned lunatic asylums . . . there are plenty of places in this world we instinctively know are utterly terrifying. But not all buildings wear their true colors on their sleeves. Every now and then, some place that seems normal and sane will turn out to secretly be a horror pit of screaming nightmares.
10. The Finnish Museum Infested With Gigantic Spiders
A grand old building in the heart of Helsinki, Finland's Natural History Museum is one of the capital's premier tourist attractions. It's also a place where no arachnophobe should ever set foot. The building is home to a gigantic colony of extremely venomous, near-immortal super-spiders.
Known as the Chilean recluse spider, the creatures are normally only found in South America. Unfortunately for Finland, some eggs made their way into a shipment of wood chips the museum ordered in the 1960s. They hatched, and the spiders escaped into the museum. By 1970, the place was overrun with them. In 2016, they're not only still there—there are more of them than ever.
The trouble is that the Chilean recluse spider is almost indestructible. Females have been known to survive without food or water for 755 days. They can deal with extreme temperature changes and can lay up to 2,250 eggs in a lifetime. As an added bit of freaky detail, they can grow to up to 10 centimeters (4 in), and their bite will leave you howling in agony (if it doesn't kill you outright).
On the plus side, the recluse spider gets its name by hiding away from humans. In the 50-plus years the museum has been infested, only one bite has ever been recorded. This is extremely good news, as the museum is built above a series of tunnels linking many buildings in Helsinki. The BBC has speculated that it's only a matter of time before the colony expands outward into other parts of the city center . . . if it hasn't done so already.
9. The American Dam Stuffed With Corpses
You've probably heard the rumors about dead workmen entombed inside the Hoover Dam. Those stories are exactly that: stories that have no basis in fact. At least, not where the Hoover Dam is concerned. Go visit the Fort Peck Dam in Montana, and you'll be looking at a gigantic tomb stuffed full of dead guys.
On September 22, 1938, the dam was the site of an infamous local disaster. The night before, workmen had noticed the structure was starting to bow, shifting 2 meters (6 ft) from its original position. At 1:15 PM the next day, just as the district engineer arrived to inspect the problem, the whole thing gave way with a terrible roar. It's estimated that 4 billion liters (1 billion gal) of water, mud, and concrete suddenly spewed out into the Missouri River, destroying everything in its path. Eight men who stood in the way disappeared into the sludge. Only two bodies were ever found.
While plenty of dams have similar disasters in their history, what happened next makes Fort Peck Dam eerie. The sludge was recycled back into the dam's construction, along with the six bodies lost within it. To this day, the corpses of the six drowned men remain part of the dam itself, like gruesome Easter eggs hidden in the concrete.
8. The London Picnic Spots Built Over Gruesome Mass Graves
If you're ever in London for the summer, one of the best things you can do is grab a drink and head to one of the city's many picnic spots to relax with the locals. Provided, that is, that you can ignore the screaming mess of horror hidden just below your feet. A 2014 study of London's plague pits found that dozens of modern picnic spots were built over the site of centuries-old mass graves.
Like most of Europe, London got hit hard by the Black Death. In the 1665–1666 outbreak alone, around 15 percent of the city's population died in agony. The infected would come down with a fever and sharp pains that would build to vomiting and delirium. Huge, painful buboes would swell up under the skin, full of foul-smelling liquid. Within a week, some 60 percent of victims would be dead.
