Eastern Europe is rich in history and natural beauty. Many different cultures have influenced him, from the ancient Greeks to the Ottomans and the Soviets. It therefore has an unusually complex history filled with war, bloodshed and mystery. Eastern Europe’s most famous ruin is Pripyat, the city abandoned after the Chernobyl nuclear disaster, but it’s just one of many desolate and terrifying places in this part of the world.

So, from the crumbling ruins of a genocidal dictator’s lair to a cave believed to be the entrance to hell itself, here are ten of the spookiest and most mysterious places in Eastern Europe, including: both artificial and natural.

Related: 10 spooky mysteries from around the world, including the house of wailing

ten Doftana Penitentiary, Romania

Nicknamed the “Romanian Bastille” for its use as a brutal political prison, Doftana Penitentiary began life as a housing complex for workers from a nearby mine. In 1921, however, the Romanian king converted it into a prison for communists. With eight wings, 308 cells and a defensive wall, Doftana was a truly intimidating place. Its most famous inmate was Romania’s future general secretary, Nicolae Ceausescu.

These political prisoners, many of whom were tortured to renounce their ideology, created a famous secret magazine using old cigarette papers. Earthquakes strike Doftana frequently, such as in 1940 when more than 300 prisoners were injured. It was closed in 1947 and turned into a museum by the new communist government. However, in 1989, Doftana was abandoned for good, and it is now a maze of crumbling detention cells, iron bars, and hallways. Composer Alfred Mendelsohn wrote a symphonic poem inspired by Doftana, which captures the dark history of this brutal political prison ravaged by earthquakes.^[1]

9 Buzludzha Monument, Bulgaria

While Russia is full of old Soviet ruins, the most extraordinary and terrifying Soviet relic of all is found in Bulgaria. Known as the Buzludzha monument and built to celebrate Bulgaria’s communist history, it was completed in 1984. The shape of the huge concrete chamber is reminiscent of a UFO. But its interior was decorated with vast, intricate mosaics by Karl Marx and Vladimir Lenin comprising more than two million individual pieces.

In 1989, like most Soviet superstructures, Buzludzha was completely abandoned. Its once exquisite murals and mosaics have almost completely crumbled and the huge glass ceiling has shattered. In winter, the central chamber is filled with snow, and looters have stripped away all valuable materials like copper. While the monument’s tower remains standing, its red star was destroyed by visitors who believed the star was made of real rubies. There is perhaps no better testament to the legacy of the Soviet Union than this mysterious otherworldly ruin in the middle of the Bulgarian countryside.^[2]

8 Island of Daksa, Croatia

Daksa is an uninhabited island located just offshore from Croatia’s most beautiful city, Dubrovnik. It has a ruined Franciscan monastery built in 1231, as well as the remains of an ancient fortress, a villa and a small lighthouse. This beautiful island is for sale at a price of just over two million dollars. What might surprise you is that Daksa has been on the market for over two decades and has yet to find a buyer.

The reason for this is that Daksa Island has a disturbing and bloody history that has alienated any potential buyer. In 1944, Dubrovnik was liberated from the Germans by Communist soldiers, who quickly rounded up suspected Nazi sympathizers and rowed them to the island of Daksa. These prisoners, including several priests and the new mayor, were summarily executed by firing squad without trial. It was not until sixty years later that two mass graves were discovered in Daksa and the victims were finally buried.^[3]

seven Petrovaradin Catacombs, Serbia

Petrovaradin is a beautiful Serbian town on the banks of the Danube with a rich history dating back to the Romans. The jewel of the city is the Petrovaradin Fortress, built by the Austrians in the 17th century to guard against Ottoman invaders. It is known as the “Gibraltar of the Danube” due to its heavily fortified position and its strategic importance.

Beneath the fortress, however, lies an old mystery: the Petrovaradin Catacombs. This network of tunnels has four different floors and is over 16 kilometers (10 miles) long. Its walls are inscribed with Masonic symbols, Maltese crosses and a mysterious inscription saying “IPAM YUM”, which no one has been able to decode.

Although they were definitely used for military purposes, the catacombs were also used for other darker purposes throughout their long history. Each level is painted in a different color: the first is red, the second is green, the third is blue and the darkest is black. A popular rumor says that part of the Austro-Hungarian imperial fortune is still hidden somewhere in the catacombs.^[4]

6 Hill of Crosses, Lithuania

In the 14th century, residents of a Lithuanian town called Siauliai began placing wooden and metal crosses on a nearby hill, although no one knows exactly why. There are several legends about this hill. Some claim it is the site of a medieval church which was buried by rocks during a huge storm with the monks still inside. Others claim that the mound was formed by the bodies of thousands of pagans who were slaughtered by the Livonian Order and that these pagans and monks both haunt the hill.

The Soviet Union destroyed the Hill of Crosses four times, but Lithuanians from all over the country continued to bring crosses to the hill. After the collapse of the USSR, it was allowed to expand even further. Today, it’s a maze of life-size crucifixes, 4.5-meter (15-foot) statues of Jesus, and hundreds of thousands of smaller crosses. For some it’s a place of pilgrimage, including Pope John Paul II, but for others it’s a haunting place that’s more like a graveyard of crucifixes.^[5]

5 Vorkuta, Russia

The world is full of abandoned cities. From Pripyat in Ukraine to Craco in Italy, we know the sight of empty streets and broken windows. But Vorkuta, the easternmost city in Europe, is a completely different type of abandoned city. Located well north of the Arctic Circle, Vorkuta is a collection of towns built around Russia’s declining coal industry. It was used as a gulag in the 1950s and less than half of the original mines are still operational.

What makes Vorkuta so captivating compared to other forgotten cities is its climate. With temperatures dropping as low as -50°C (-58°F) and weeks without sunshine in winter, Vorkuta looks less abandoned than destroyed by a natural disaster. Indeed, the sight of couches, tables, and chandeliers coated in thick frost is somehow more shocking than if they had simply been left alone to decay. Vorkuta was literally frozen in time, almost perfectly preserving a Soviet coal community that we can marvel at.^[6]

4 Devil’s Throat Cave, Bulgaria

The Devil’s Throat cave in Bulgaria is believed to be where Orpheus entered the underworld to save his dead wife, Eurydice. Located in the Bulgarian Rhodopes, the cave gets its name from the fact that its entrance resembles a demonic face. Additionally, the water of the Trigrad River falls almost 44 meters (150 feet) directly downwards, this huge drop being the eponymous “throat” of the devil.

This underground waterfall lands in the Hall of Thunder, so called because of the deafening noise it produces. A funnel 90 meters (300 feet) deep then channels the underground water, resurfacing in a chamber separate from the cave system. This is where things get even more terrifying. Nothing carried into the Devil’s Throat Cave by the Trigrad River never appears on the other side. People have tried using wood, dyes and floats, but whatever hides underground stays there. You can see why this cave has been mythologized in Bulgarian folklore as an entrance to hell itself.^[7]

3 Vila Rebar, Croatia

Vila Rebar looks more like the lair of a comic book villain than an actual location. Originally built in the 1930s, it was taken over by Croatian dictator Ante Pavelic during World War II. Pavelic was an admirer of Hitler, and under his leadership over 600,000 Serbs were killed in one of the least known genocides in history. The fascist dictator was also deeply paranoid about his safety and so built an extensive network of underground tunnels under Vila Rebar. The extent of this underground lair has not yet been fully documented, although it is believed that it once led to nearby military bases and also served as an escape route.

After Pavelic’s dismissal, Vila Rebar was turned into a hill station, but it was partially destroyed by fire in 1979 and left to rot. Now only the stone foundations of the original villa remain. However, Pavelic’s network of tunnels is still intact. Its walls have been spray-painted with disturbing images and locals tell horrifying ghost stories about this vast and mysterious maze.^[8]

2 Hoia Baciu Forest, Romania

While Japan’s suicide forest has a reputation as the scariest forest in the world, it’s because of its use more than because of the forest itself. However, the Hoia Baciu forest in Romania is a much more terrifying place. Located in the heart of the Carpathian Mountains of Transylvania, the homeland of Dracula, Hoia Baciu dates back over 55,000 years.

There are many local legends about Hoia Baciu, such as that of a five-year-old girl who got lost and returned five years later with no memory of where she was. Farmers are also known to stay away from the Hoia Baciu. But even more than those haunting tales, it’s the forest’s appearance that makes it so frightening. Its ancient trees are gnarled and twisted – none of them growing straight – and they are often draped in thick fog. Scariest of all is the large clearing in the center of the forest where nothing grows, without any scientific explanation.^[9]

1 Mamula Fortress, Montenegro

On an island formerly known as Lastavica, just off the Montenegrin coast, lies an old castle with dark secrets. Known as the Mamula Fortress, it was built by the Austro-Hungarian Admiral Lazar Mamula in the 1850s. Curiously, not a single cannon shot was ever fired from the fortress walls, nor attacked . The Austro-Hungarians used it as a prison during World War I, and during World War II it was used by Mussolini’s fascists as a concentration camp.

Measuring 16 meters (50 feet) and nearly 200 meters (700 feet) in diameter, this daunting fortress housed around 2,000 prisoners. These detainees, who included women and children, were starved, beaten and tortured. More than 130 inmates died at Mamula and their descendants still visit the island in tribute. In 2019, the Montenegrin government revealed plans to build a luxury resort on the island. This was understandably met with disgust, and it is certainly hard to imagine people partying in the same halls where political prisoners starved to death less than eighty years ago.^[10]