Have you ever found yourself visiting your favorite destinations only to realize you're revisiting the same popular spots time after time? Or perhaps you're yearning for a fresh and exciting new location to explore, even within your own country.
Some of the locations featured here have been kept under wraps for many years, while others have ancient origins and remain relatively unknown. For your next adventure, why not uncover these secret spots and hidden treasures?
10. The Aventine Keyhole—Rome, Italy

In the charming city of Rome, there's an unremarkable green door tucked at the end of a quiet cul-de-sac. You could easily walk by it without giving it a second thought. But this is no ordinary door—through its keyhole, you'll catch a perfect, albeit small, glimpse of one country and two nation-states, with the iconic St. Peter’s Basilica neatly framed in the middle.
This door opens to the Priory of the Knights of Malta, a renowned religious order. Peering through its keyhole reveals a unique sight—Italy, Malta, and Vatican City all in one view! Originally belonging to the Knights Templar in the early 12th century, the property was later handed over to the Knights of Malta in the 15th century.
The striking building you’ll see today is a church called Santa Maria del Priorato, designed by the famous engraver and architect Giovanni Battista Piranesi in the 18th century. The church’s architecture draws inspiration from ships and the sea, based on the tradition of comparing Aventine Hill to a ship.
The keyhole view aligns perfectly with the gardens, with the Vatican in the distance. It remains unclear whether this was an intentional design or simply a fortunate coincidence.
9. Passetto del Biscione—Rome, Italy

Visitors wandering through Campo de Fiori in Rome might unknowingly pass by a hidden passageway connecting Piazza del Biscione to Via di Grotta Pinta. This narrow corridor, known as Passetto del Biscione, holds an intriguing historical significance.
It’s thought that the passageway was named after the symbol of the Orsini family—an eel. The Orsini family constructed a palace over the ruins of Rome’s earliest theater, the Theater of Pompey. However, in 1796, this passageway became the site of a miraculous event.
Within the narrow passage, there’s an image of the Madonna, which, according to reports, caused her eyes to move in the late 18th century. This extraordinary event drew devout Christians from across the city, but the alley’s secretive location made it difficult for many to witness the miracle firsthand.
After being abandoned for decades, the passageway was eventually restored to its current splendor in 2016. The image of the Madonna continues to captivate visitors to this day.
8. Hidden Staircase in Penshaw Monument—Houghton le Spring, England

Completed in 1844, the Penshaw Monument is an impressive sight atop Penshaw Hill in Tyne and Wear, England. A replica of a Greek temple, it stands at an impressive height of 70 feet (21.3 meters) and was built to honor the 1st Earl of Durham, John George Lambton.
This 200-year-old Greek-style temple hides an astonishing secret—a spiral staircase concealed within one of its massive pillars! Tragically, in the 1920s, a teenager lost his life after falling from the staircase.
The staircase was sealed off for safety reasons following the tragic incident and remained closed for nearly 90 years, save for a brief period in the mid-1960s when vandals broke the lock. When the National Trust assumed responsibility for the monument’s upkeep, the staircase was reopened in 2011. However, it’s only accessible on specific days, and visitors must pay a fee to climb it!
7. Traboules: The Hidden Passages of Lyon—France

In Lyon, France, a network of secret passageways once provided a discreet and secure route for silk workers to transport their goods between markets. These traboules are now partially accessible to the public, winding through various buildings. The term 'traboules' is derived from a distorted form of the Latin 'trans-ambulare,' which means 'to pass through.'
Some of the earliest passageways date back to the 4th century, originally built to give people direct access to the town’s fresh water supply, bypassing the streets. It’s believed that there are approximately 400 traboules in Lyon, but only a select few are open to the public—these are marked with a special identification seal. The rest remain hidden behind locked gates and doors.
In the 19th century, the silk trade in Lyon’s Croix-Rousse district flourished. The traboules and courtyards that traversed this area became bustling hubs for local silk weavers, or 'Canuts.' In the 1830s, Lyon was home to about 25,000 silk looms, and as more silk shops opened, merchants started exploiting the weavers, paying them meager wages and offering poor working conditions.
Faced with fierce competition, greedy merchants, and an unstable economy, the silk weavers decided to revolt. They shut down their workshops, gathered in the streets, and armed themselves with weapons from the local armory, demanding better wages and working conditions. However, their rebellion was brutally suppressed.
Although around 10,000 Canuts were sentenced to criminal deportation, their courageous resistance sparked future labor uprisings.
6. Scotland’s Secret Bunker—Airdrie, Scotland

Passing by a quaint cottage in Scotland, one would never suspect that a tunnel lies beneath, leading to a massive secret bunker. Covering 24,000 square feet (2,230 square meters) of space, Scotland’s Secret Bunker remained hidden for over 40 years. Located 100 feet (33.3 meters) underground, the bunker features two expansive levels, each as large as a soccer field.
In the event of a nuclear war, this secret bunker would have served as the command center for the country’s authorities. It was also a crucial part of the ROTOR system, a vast initiative to upgrade the UK's radar network following World War II. The system consisted of multiple locations featuring massive underground bunkers capable of surviving bombings.
Now outdated as a government refuge, the bunker has been transformed into a museum filled with Cold War artifacts. Many of the items, however, are replicas and occasionally inaccurate. Despite this, the bunker houses a captivating collection of military vehicles from various countries, including Britain’s only Russian anti-aircraft missile.
5. Secret Art Deco Tunnel beneath the New Yorker Hotel—Manhattan, New York

The striking red sign of the New Yorker Hotel is an iconic feature of West 34th Street in New York. While the hotel is often photographed as a city landmark, many aspects of its history remain shrouded in mystery. Among its many secrets is a stunning Art Deco tunnel located beneath West 34th Street.
Behind a sealed door lies a passageway filled with vintage hotel chairs, carpets, fixtures, and Art Deco tiles. As you walk through this tunnel, you’ll find yourself traveling directly beneath West 34th Street in a zig-zag pattern. At the far end, a brass door leads out to the platform of the E subway line.
The hotel's archives contain a 1930s brochure advertising the tunnel, describing it as 'so convenient!' It highlights the tunnel as one of the hotel's top features, connecting directly to Penn Station and extending all the way to the Empire State Building. Though the tunnel is not accessible to the general public, visitors can explore it on a guided tour.
4. Drakelow Tunnels—Cookley, England

At Kingsford Country Park in North Kidderminster, England, many visitors may unknowingly walk above a hidden military complex. Located near Birmingham, these underground tunnels carry a fascinating history.
Constructed in the early 1940s, these tunnels were designed to serve as a 'shadow factory' for the car manufacturer Rover. The concept of a shadow factory was introduced in 1930s Britain, facilitating the exchange of machinery and expertise across industries, where specialists could 'shadow' one another.
Spanning miles (5.6 kilometers), the tunnels played a crucial role during World War II and into the 1950s. By 1961, however, some sections were repurposed by the British Government as secret 'shadow government' command centers. During the Cold War, these tunnels were intended as a refuge for governing the country in the event of an emergency.
The Drakelow tunnels remained hidden from the public until their decommissioning in 1993. At that time, the tunnels and their equipment were sold to a private purchaser. Since then, the Drakelow Tunnels Preservation Trust has been diligently working to restore the complex, with plans to open a Cold War museum for visitors.
Though it's an extensive undertaking, portions of the tunnels are open to the public, offering a wealth of history to explore and numerous secrets to be discovered underground!
3. The Hidden Beach—Islas Marietas, Mexico

Tucked away on a lush island, Playa del Amor is a secluded beach known for its ample sunshine and crystal-clear waters. Referred to as the Hidden Beach, Playa del Amor is located in the Marietas Islands—an uninhabited archipelago formed by underwater volcanic activity.
Situated about 22 miles (35.4 kilometers) to the west of Puerto Vallarta, Mexico, the Hidden Beach feels like a scene straight out of a fantasy film. With its pristine white sand cavern and turquoise waves lapping the shore, this secluded paradise is an idyllic retreat for a romantic getaway.
Completely concealed from view, the aptly named Hidden Beach can only be accessed through a water tunnel that connects it to the Pacific Ocean. With approximately six feet (1.8 meters) of space above the water, you can either swim or kayak your way to this secluded paradise.
2. Hidden Newgate Prison Cells—London, England

London's Newgate Prison was so notorious that it’s enough to make anyone thankful to live in the present day! Located near St. Paul's Cathedral, this grim institution housed the city's most dangerous criminals for over 700 years before being closed and demolished in 1904.
Built in the late 12th century by the orders of King Henry II, Newgate Prison became infamous over the centuries for holding the most dangerous criminals, including highwaymen, murderers, and cutthroats.
Today, the site of this once-dreaded prison is home to London's Central Criminal Court, known as the Old Bailey. There's little left of the original prison except for a small plaque on the Court's wall, though remnants of the Eastern Wall can still be seen on Amen Court, a nearby residential street.
It is said that the final remnants of the old Newgate jail cells lie hidden beneath the Victorian-era Viaduct Tavern. These small, gloomy cells offer a glimpse into the harsh reality of life in one of London’s most dreaded prisons from centuries past. Rumors suggest these tunnels might be linked to the main prison by an underground passage, though whether this is fact or simply a local tale remains uncertain.
Although the Viaduct Tavern has been the subject of various rumors, such as a brothel and opium den operating above the pub, it’s likely that the enigma of the eerie cells beneath will never be fully unraveled. If you’re curious to visit these hidden chambers, a friendly chat with one of the bartenders might just be the way to go!
1. The Whispering Gallery of Loggia dei Mercanti—Milan, Italy

Beneath the Palazzo della Ragione lies an open-air space known as the Loggia dei Mercanti. This is not just an ordinary space, but a hidden communication system. If you whisper to the columns, the archway will carry your voice to a strategically placed listener on the other side.
As part of the medieval square, the Loggia serves as a whispering gallery. This extraordinary acoustic phenomenon occurs beneath archways and domed structures, enabling even the softest sounds to travel across great distances.
Numerous tales surround the whispering gallery, including stories of how Renaissance and medieval merchants would take advantage of the hidden communication system to share secrets. Other legends tell of forbidden lovers who used the Loggia to exchange whispered romantic words.