Catacombs—underground rooms and tunnels used as cemeteries—date back to first-century Rome, but the most famous (and infamous) were created across Europe in the 17th century. Overcrowding in Paris’s more traditional burial spaces, as well as sanitation issues, led authorities to turn the miles of tunnels connecting quarries under the city into crypts. It’s believed that more than six million people were laid to rest in this underground labyrinth. In some places, bones and skulls line the walls, with a few even crafted into intricate works of art.
While Paris might get all the headlines, such sprawling crypt networks exist all over the world. Take the city of León, Mexico, where the beautiful Templo Expiatorio, a Neo-Gothic church, also provides entry to an underground world. Formed by a connection of seven different crypts, this catacomb has cramped, dark corridors that hold the remains of nearly 2,000 people. Elsewhere, the Catacombs of Washington, D.C., were created by Franciscan monks who wanted to channel the Holy Land for those who couldn’t afford a trip overseas. From catacombs across Malta to little-known collections of bones beneath monasteries, here are some of our favorite chill-inducing labyrinths of the dead.
1. ‘Catacombs’ of Petrovaradin Fortress 📍 Petrovaradin, Serbia
Petrovaradin Fortress sits along the Danube River, right where the old town of Petrovaradin meets Novi Sad, Serbia’s second-largest city. Construction of the fort began in 1692, and its strategic importance earned it the nickname “Gibraltar of the Danube.” Most visitors never learn about the underground military galleries hidden beneath it: a four-story network of passageways that stretch roughly 10 miles in total. The walls bear the Maltese cross, various Masonic symbols, and a mysterious inscription once used by alchemists. Each level is marked by a different color, with the fourth (black) level considered the most mysterious, home to the so-called “Kaiser Well,” that Habsburg rulers allegedly once drank from. Local legend holds that part of the Austrian Imperial Treasury was hidden here to keep it from Napoleon, and that some of it is still lost in the tunnels today.
2. Catacombs of Old St. Patrick’s Cathedral 📍 New York, New York
The catacombs beneath Old St. Patrick’s Cathedral are among a select few in the entire United States, and their history is tightly bound to New York City’s early Catholic community. Bishop John Hughes—known as “Dagger John” for his sharp tongue—once defended the church from an anti-Catholic mob with armed parishioners stationed outside. Irish, Italian, Hispanic, and Asian immigrants all found refuge here, and the community’s most devoted members were eventually entombed in the cathedral’s crypts. Notable occupants include Congressman John Kelly, an adviser to Abraham Lincoln; the Delmonico family, founders of New York’s oldest surviving restaurant; and Civil War veteran General Thomas Eckert, whose family vault still holds original Thomas Edison light fixtures. The Eckert vault also contains tile work by engineer Rafael Guastavino, the same craftsman behind Ellis Island and the City Hall subway station. For over 200 years the catacombs were seen only by clergy and the families of the entombed, but they are now open to the public for candlelight tours.
3. Catacombs of Saint Gaudiosus 📍 Naples, Italy
In the 430s CE, King Genseric of the Vandals set a Tunisian bishop named Septimius Celius Gaudiosus adrift on an oarless ship after he refused to adopt the Vandals’ Arian faith. Gaudiosus eventually washed up near Naples, where he founded a monastery. After Gaudiosus passed away, he was buried, along with other African refugees, in Greek-era catacombs in what is now the city’s Sanità district. The site holds some of the world’s oldest surviving Christian art, but it is most infamous for what happened there centuries later. In the 17th-century, Dominican monks reopened the abandoned tombs and started up a widespread mummification process: Bodies were drained of fluid over a year, plastered over, and displayed with only the preserved head sticking out of a fresco depicting the rest of the body as a skeleton. One artist, Giovanni Balducci, was so taken with the honor of painting a fresco that he asked to be buried there himself rather than accept payment for his work. Until recently, very few knew of the catacombs’ existence underneath this bustling Naples neighborhood. A local cooperative of archaeologists and art historians first began to excavate and give tours of the complex in 2006.
4. St. Cataldus Catacombs 📍 Rabat, Malta
Dedicated to an obscure Irish saint whose veneration on Malta likely arrived with the Normans, this small church is overshadowed by Rabat’s more famous St. Paul’s and St. Agatha’s catacombs nearby. However, its underground chamber holds one of the finest surviving examples of an agape table: a circular rock-hewn platform used for early Christian funerary rituals, where relatives would gather annually on the anniversary of a burial to commemorate the dead. A steep staircase inside the church leads down to Baldachin-style canopied tombs dating from the late 2nd to 3rd centuries, with dove imagery marking one corner.
5. Fontanelle Cemetery Caves 📍 Naples, Italy
This cave complex was first used as a secondary burial ground when Naples’s churchyards started to overflow in the 1500s. However, the majority of its 40,000 residents came from the devastating plague outbreak of 1656 and smaller cholera epidemics in the 1830s. Over time, a uniquely Neapolitan “cult of the dead” grew around these departed souls: Starting in 1872, a priest named Father Gaetano Barbati began cataloging and shelving the anonymous remains, and women in the neighborhood started naming skulls, bringing them offerings, and asking favors—placing wishes written on rolled papers into the empty eye sockets. The Cardinal of Naples ordered it closed in 1969 to end the community’s troubling obsession with lucky skulls, but it is now reopen for visits by reservation only.
6. Santa Maria delle Anime del Purgatorio ad Arco 📍 Naples, Italy
Smaller and more intimate than the Fontanelle caves, this burial place dates to 1638, when a lay group called the Congrega di Purgatorio ad Arco began burying Naples’s poor and unclaimed—a mission that grew urgent after the Black Death hit. In Catholic doctrine, souls buried without a proper marker were thought to languish in purgatory unless the living prayed for them, giving rise to the “Neapolitan Skull Cult.” Visitors adopted specific skulls, brought them gifts, and asked favors in return, believing the dead were closer to God and endowed with saintly power. The most famous adopted skull, “Princess Lucia” (the “Virgin Bride”), still draws women seeking marital help and is often found wearing a tiara or veil.
7. Catacombs at Templo Expiatorio 📍 León, Mexico
Templo Expiatorio’s white walls and huge circular rosette windows echo Notre-Dame in Paris, but the church’s real point of interest lies beneath it: a labyrinth of catacombs formed from seven interconnected crypts that hold the remains of 1,919 people. The crypts were designed to support the temple’s construction, which began in 1924 but was interrupted twice—first by a major flood, then by the religious conflict of Mexico’s Cristero War—before finally resuming in 1930. For decades, locals joked that the temple’s completion would herald doomsday, but its completion in 2012 arrived (thankfully) with no catastrophe.
8. Catacombs of Washington, D.C. 📍 Washington, D.C.
Beneath the Franciscan Monastery of the Holy Land in America, a dimly lit maze of wall graves recalls the ancient catacombs of Rome—except these aren’t ancient at all. They were built at the turn of the 20th century by Franciscan monks who wanted North Americans to experience a piece of the Holy Land without the transatlantic trip. These “catacombs” are almost entirely fake, cast from cement rather than carved from soft rock, and much smaller than their Roman namesake. There’s one exception: With official Papal blessing, a genuine skeleton believed to belong to a second-century child martyr was transported here from Rome in 1929. Roman architect Aristides Leonori designed the space using measurements and photos of the real thing, and three architecturally distinct sections represent various chapters from early Christian lore.
9. Warstone Lane Cemetery Catacombs 📍 Birmingham, England
Tucked into Birmingham’s Jewellery Quarter—best known for its engagement rings and promises of new beginnings—the neighborhood’s Warstone Lane Cemetery honors the past. Opened in 1848, the cemetery took burials until 1982, housing bodies in tiered, semicircular catacombs that resemble a Roman amphitheater. However, the grandeur is deceiving: Most of the tombs hold the city’s poor—victims of 19th-century industrial overcrowding rather than members of the city’s elite. One notable exception is John Baskerville, the celebrated English typographer, whose remains were moved here in 1897 after the church that originally housed his crypt was demolished. Though the catacombs were once open for public tours, they have since been sealed shut, leaving their dark tunnels up to the imagination.
10. Maltese Catacomb Complexes 📍 Rabat, Malta
From the 3rd to 6th centuries, the Roman city of Melite (now Rabat) developed an elaborate burial system on its outskirts, as Roman law barred burials within city limits. Known today as St. Paul’s and St. Agatha’s catacombs, the complex holds tombs for more than 1,000 bodies across 2,200 square meters, designed with both private family spaces and large communal halls for festivals and rituals. Doric-style pillars frame circular stone tables and couches that were likely used in burial rituals, and in some sections, corridors run a full three stories underground. Abandoned in the 7th century during Byzantine rule, the catacombs were eventually reopened for Christian pilgrimage in the 12th century.
11. Igreja de São Francisco Catacombs 📍 Porto, Portugal
Igreja de São Francisco may look Gothic on the outside, but it’s dripping in Rococo gold on the inside: A whopping 400 kilograms of it coats the church’s ornate wood carvings and statues. Below its three interior chapels, catacombs hold tombs for members of the Franciscan order awaiting judgment day; tucked in a corner of the crypt, a grated glass window in the floor lets visitors look down at piles of human bones. In one of history’s odder footnotes, when Napoleon’s forces conquered Porto, he reportedly converted the opulent church into a stable for his horses.
12. Ta’ Bistra Catacombs 📍 Mosta, Malta
Hidden beneath a traditional Maltese farmhouse, the Paleochristian Ta’ Bistra Catacombs date to the 4th century and were rediscovered in 1891, though not properly investigated until 1933. Stretching 300 feet through 16 chambers with 57 tombs, they’re the largest catacomb complex found outside Rabat and offer clues to the burial customs of Malta’s earliest Christians. The site hasn’t had an easy history: The farmhouse built on top damaged some of the ancient chambers, the tombs were at times used to pen animals, and during World War II, they served as an air-raid shelter. The farmhouse has since been converted into a wheelchair-accessible visitor center.
13. The Sacconi Rossi Crypt 📍 Rome, Italy
Tiber Island, long considered sacred, hides one of Rome’s best-kept secrets: the burial crypt of the Brotherhood of the Devotees of Jesus at Calvary—nicknamed the “Sacconi Rossi” for the red hooded capes members wore. Founded in 1760, the group’s mission was to recover and restore the dignity of unclaimed bodies pulled from the Tiber River, often carrying out nighttime torchlit processions to do so. In 1784, they built a crypt beneath their headquarters near the Basilica of St. Bartholomew, decorating its walls and niches with the bones of deceased brothers. Napoleon’s troops later damaged the crypt and turned the space into a dormitory during the 1849 Roman Republic uprising. Each year, on the evening of November 2nd, a candlelit processions descends from the church of San Giovanni Calibita to bless the Tiber’s waters in memory of those who drowned.
14. The Catacombs of St. Peter’s Abbey 📍 Salzburg, Austria
Carved into the Mönchsberg mountain in the 1100s, these catacombs served as a sacred burial site and hermitage for Christian mystics. They are also tied to St. Peter’s Church—founded in the 7th century and still home to the oldest monastic order in the German-speaking world. Preserved altars, relics, tombs, inscriptions, and faded murals span two publicly accessible levels: the “Gertrauden Chapel,” dating to 1178, and the older “Maximus Chapel” nearly 40 steps above it. Michael Haydn and Mozart’s, sister Nannerl, are both buried near the entrance.. The site also has a cameo in The Sound of Music when the von Trapp family hides from Nazis there before fleeing to Switzerland.
15. Melník Chapel of Bones 📍 Melnik, Czechia
Originally meant as a holy burial ground for Bohemian royalty, the crypt beneath St. Peter and Paul’s church in Melník took a grim turn in the 1520s. Plague forced the wholesale exhumation of surrounding cemeteries, and some 15,000 bodies were cleaned and dumped into the vault. It sat bricked up and forgotten from the 1780s until the 1910s, when Czech anthropologist Jindřich Matiegka reopened it to assemble his very own ossuary. He stacked roughly 10,000 skeletons into a single towering pile over six feet tall and arranged another 5,000 into a cross, a heart, and a tunnel of leg bones (meant to symbolize resurrection). Matiegka signed his masterwork with the Latin phrase “Ecce mors” (“Behold death”) spelled out in bone.
16. Klatovy Catacomb Mummies 📍 Klatovy, Czechia
Between 1676 and 1783, more than 200 Jesuit priests and local noblemen were laid to rest in oak coffins beneath a Jesuit church in the town of Klatovy. Thanks to a clever system of ventilation ducts and wells, many of their bodies mummified naturally over time, leaving clothing, shoes, and jewelry intact. Unfortunately, a 1930s reconstruction of the church roof disrupted that delicate airflow, and much of the collection began to decay; 140 bodies too damaged to display were reburied collectively in 1937 at a graveyard site marked with a commemorative stone. Around 30 mummies remain on view today in glass coffins, alongside forensic exhibits including a facial reconstruction of one of the preserved female mummies.
17. Museum Romeinse Katakomben (Roman Catacombs Museum) 📍 Valkenburg, Netherlands
Descend below the pretty Dutch town of Valkenburg and you land, at least in spirit, in Rome circa 400 AD. Jan Diepen, son of a wealthy Dutch textile magnate, was fascinated by the catacombs of Rome and began building a faithful reproduction inside a disused quarry in 1908, later enlisting renowned architect Pierre Cuypers. Rome and the Vatican were impressed enough by its accuracy to help fund its completion, and the replica catacombs opened to the public in 1910. Hallways from 14 different Roman catacombs were condensed and shortened for museum presentation, and candlelit tours still wind past ghostly frescoes, columbariums, and eerily lifelike marble statues.
18. Capuchin Monastery Catacombs 📍 Palermo, Italy
In Sicily, where the line between the living and dead has always run thin, the Capuchin Monastery hosts one of the world’s strangest tourist attractions: nearly 8,000 corpses, each dressed in its Sunday best, are pinned to walls, seated on benches, or laid in open coffins. These catacombs are divided by category—religious figures, professionals like doctors, and a room reserved for women, virgins, and infants—with the oldest corpse belonging to a friar who died in 1599. The dry atmosphere allowed for natural mummification: Priests initially let bodies drip-dry on shelves for a year before rinsing them in vinegar and redressing them for eternity. The most recent, and most famous, resident is two-year-old Rosalia Lombardo, embalmed in 1920 using a formula—formalin, alcohol, glycerin, salicylic acid, and zinc salts—so effective she’s nicknamed “Sleeping Beauty.”
19. Catacombes de Paris 📍 Paris, France
The Paris Catacombs are the public-facing sliver—about a mile—of a roughly 200-mile network of old quarry tunnels beneath the city. As Parisian cemeteries like Les Innocents became dangerously overcrowded in the 18th century, officials began relocating bones from condemned graveyards into abandoned quarries. The ossuary now holds the remains of six to seven million Parisians, including, likely, figures such as fabulist Jean de La Fontaine and architect Salomon de Brosse. The catacombs opened to the public in 1867, but beyond the official tour route, the wider tunnel network has its own subculture of “cataphiles.” In 2004, police doing a training exercise stumbled on a fully wired 500-square-meter cavern cut into an unmapped section, complete with a movie screen, a stocked bar, and a note reading, “Do not try and find us.” The site was closed for several months in 2009 after vandalism and the theft of several skulls.