Major cities bustle with traffic, trains and people every day. Tourists, for their part, trickle in to check out the architecture, museums and landscape, too. With so much activity, it’s easy to forget what’s happening underground in some of the world’s biggest cities, where subterranean rivers flow just beneath our feet.
20. Park River – Hartford, Connecticut
This waterway in Hartford, Connecticut, earned a pretty unsavory nickname – the Hog River. It wasn’t an unwarranted moniker, though. Park River had become the place to dump both industrial waste and sewage, which left it heavily polluted and incredibly smelly. As such, the U.S. Army Corps of Engineers decided to do something about it in the 1940s.
In what was one of the Corps’ priciest and biggest projects at the time, teams worked to reroute the Park River so that it flowed entirely underneath Hartford. Today, it sits between 30 and 50 feet underground – snaking its way beneath the state capitol building and the city’s main library. But urban explorers do journey down into the depths to kayak around the subterranean waterway. And according to John Kulick from the tour company Huck Finn Adventures, the polluted river is home to fish and eels nowadays.
19. Minetta Brook – Manhattan, New York
It’s hard to picture Manhattan as anything other than a bustling, built-up metropolis. But in the 1700s people living on the island were farmers – not city slickers. Furthermore, many of them relied on the Minetta Brook to water the plants they grew in an area that today is Greenwich Village.
Of course, Manhattan didn’t stay an agricultural oasis for long, and the Minetta Brook suffered for it. The waterway became too polluted, so it was re-routed to flow into New York’s drainage and sewage system underground. Now, you’d be hard-pressed to find even a trickle of the Minetta Brook, which has been paved over as part of the concrete jungle.
18. Shibuya River – Tokyo, Japan
If you’ve ever been to Tokyo, then looking at an old map of the city – when it was known as Edo – will be shocking. Rivers and canals once flowed through much of the Japanese capital. In fact, a Swiss envoy named Aime Hubert visited in the 1860s and said that he hadn’t seen anywhere in Europe like Tokyo except Venice, Italy.
As it turns out, more than 100 naturally carved rivers and human-made canals now hide under Tokyo’s surface. The Shibuya River is just one of them, and its cover-up occurred relatively recently. The city paved over to build the national stadium and access roads necessary to host the 1964 Olympics there.
17. River Sheaf – Sheffield, England
The River Sheaf fell victim to industrial activity that once boomed in Sheffield, England. The main polluting culprit was the city’s metalworks, which pumped the waterway full of pollutants. Eventually, the Sheaf ended up beneath a series of culverts because it got so heavily damaged by all the manufacturing waste.
But the Sheaf isn’t Sheffield’s only river to be dealt a sad fate. Two other waterways – the Porter and the Don rivers – snake their way under the center, too. But some locals have begun to push for culvert removal so that all of Sheffield’s rivers can flow freely and visibly for the first time in decades. Furthermore, work to clean up the waterways has been ongoing in recent years.
16. Sunswick Creek – Queens, New York
This is another New York City borough which once had its own source of flowing water. Old maps of the area depict a waterway called Sunswick Creek until the 1870s. By that time, though, the Big Apple had already begun to explode in size. And concrete later became more favorable than a natural supply of freshwater.
Urban explorer Steve Duncan spoke to National Geographic about Sunswick Creek after venturing into the subterranean waterway to snap photos. He said that it looked like the cover-up had happened in phases. Regardless, the creek now trickles through a series of underground pipes similar to those that funnel sewer water out of developed areas.
15. Bottini River – Siena, Italy
Picturesque Siena in Italy sits on top of a hill, which isn’t where you’d expect to find a flowing river. Indeed, there wasn’t one when the city came to be – but forward-thinkers from the Middle Ages had a solution. They etched out over 15 miles of tunnels underneath the town to supply residents with the water they needed.
It took three centuries to create the Bottini River, but the workmanship has endured – and continues to serve Siena’s residents today. Rainwater and natural spring water flow through the miles-long tunnels and into the Tuscany city’s homes. Nowadays, however, the locals get most of their water from the nearby Mt. Amiata.
14. River Fleet – London, England
River Fleet is among the world’s most well-known subterranean waterways. Springs feed into the river at its base in Hampstead Heath, pushing it through its pathway through London and eventually into the Thames. But once the river served as more of an industrial sewer than a source of fresh water, it became time to cover it up.
At first, the River Fleet wasn’t completely covered. It used to emerge in central London and that spot became known as Fleet Street. But by the 1860s the entire river was hidden from view and funneled into the city’s underlying sewer system. Some have attempted to descend into the tunnels to map the River Fleet, but it’s a tough job. The tidal waterway ebbs and flows so, at high tide, the canals fill to the brim with water.
13. Tank Stream – Sydney, Australia
The British made landfall in Australia in 1788 and immediately began their search for a place to settle – specifically a location with a steady supply of freshwater. They found what they were looking for in modern-day Sydney, and the area’s river became known as the Tank Stream in recognition of how the settlers chose to store their water.
The Brits forced convicts banished to Australia to build holding containers which stored Tank Stream’s fresh water. But the waterway’s story ended in the same way as many others on this list – the river became so widely used that it began to fill up with pollutants. Eventually, its swamp-based source was drained out, and the remaining trickle became part of Sydney’s drainage system.
12. River Farset – Belfast, Northern Ireland
Belfast in Irish is Béal Feirste, which means “the sandy ford at the mouth of the Farset.” It’s an interesting name for the city – considering the river that inspired its name isn’t visible anymore. The waterway sits just a mere 23.6 inches under the surface, according to the BBC, and it has done so for 170 years.
The River Farset powered Belfast’s thriving textile mills in the late 19th century – helping make the city into the world’s most prominent linen maker. But all of this industry came at a price to the river, and it became clogged by foul-smelling pollution. The scent became so bad that city officials decided to cover the Farset. So, they used one million bricks to hide it from view for good.
11. Sawmill River – Yonkers, New York
The Sawmill River flows in the open for around 23 miles until it gets to Yonkers, which is just outside of New York City. Since the turn of the 20th century, the last 2,000-foot stretch of the waterway has been underground, which makes sense, considering Yonkers is a neighbor to the Big Apple. It also experienced rapid development to the point that the river was eventually covered by bridges and other industrial construction.
The Sawmill River didn’t just suffer from the overarching development – it was also heavily polluted. But scientists have come up with a plan to reverse the damage done to the waterway by exposing the underground stretch to sunlight. Once a $3 billion redevelopment project ends, it will flow through a new park in Yonkers – no tunnels required.
10. Neglinnaya River – Moscow, Russia
On a modern-day trip to Moscow, you can take a stroll down the Moskva River, which peacefully flows through the Russian capital. In the past, though, you might’ve opted for a walk along the Neglinnaya River instead. It carved a pathway from the north to the south of the city until it was buried underneath the surface.
At one time, the Neglinnaya River fed into the moat surrounding the Kremlin – a long-time symbol of state authority and, nowadays, the president’s official residence. However, the waterway was prone to flooding, so it was diverted to a canal and its original path was filled in. Eventually, engineers pushed it underground via vaults and tunnels, and today the Neglinnaya trickles into the Moskva through two spouts.
9. The Senne – Brussels, Belgium
The Senne once wound through Brussels and served as one of the Belgian capital’s central waterways. However, the river’s flow proved too unpredictable to support city life, as it regularly breached its banks. Plus, people dumped both household and industrial waste into the water – polluting it to the point of disuse.
The authorities in Brussels began to funnel fresh water into the city through a canal system, and they slowly covered the Senne over a six-year period from 1865. Eventually, the waters were diverted out from beneath the city so that its new subway could use the tunnels. And, according to the website Mental Floss, it took until 2007 for the polluted waters to pass through a modern sewage treatment center to cleanse them.
8. Bradford Beck – Bradford, England
You can still see a bit of Bradford Beck before it makes its descent underground. Multiple springs feed into one stream, which gathers with a few more as it journeys toward the city of Bradford. But once it arrives in the center, the Beck dips beneath the surface through a set of arched culverts.
Bradford Beck flows under the city and continues underground for approximately four miles until it empties into the River Aire. It ended up below the surface to make room for more development in the city in the 19th century, when industry was booming. At one time, though, its clear waters openly flowed through the center – powering mills and providing drinking water, too.
7. River Bièvre – Paris, France
Not all of the River Bièvre flows underground. At its source near Versailles – and the famous palace that once housed King Louis XVI and Marie Antoinette – you can catch a glimpse of the waterway as it winds toward Paris. However, once you arrive in the French capital, you won’t be able to find even a trickle of the Bièvre.
The Bièvre has been diverted multiple times to channel its water into different projects, which has weakened its flow over time. Industrial pollution necessitated pushing the water underground and into Parisian sewers, too. However, at one time, it flowed right into the Seine, and Mental Floss claims that renewal projects hope to bring it back to the light once developers have funding.
6. Waihorotiu Stream – Auckland, New Zealand
Many visitors trek to New Zealand to explore the country’s lush landscape. And, at one time, Auckland had a little bit more blue to offer its visitors. Several small tributaries fed into the Waihorotiu – a freshwater stream on which the indigenous Māori people relied. Apparently, they once bathed and gathered drinking water from the flowing creek.
If the Waihorotiu still existed today, it would run through Auckland, down Queen Street and toward the sea. But over time, construction and urbanization overtook the stream, and it now hides beneath the ground. Some hope that a renewal project could restore the Waihorotiu to its former glory but, so far, it remains out of sight.
5. River Westbourne – London, England
As this list has revealed, the U.K. capital has plenty of waterways hidden underground. The River Westbourne once proudly flowed from Hampstead through to Hyde Park, Sloane Square and then emptied into the River Thames in the heart of the city. It wasn’t just a pretty sight, either – the Westbourne also provided fresh drinking water to residents for hundreds of years.
By the 19th century, though, the River Westbourne became so polluted that no one could drink out of it anymore. Instead, it became sewer water, and it was pushed underground. This helped with the development of London, too – without a major waterway coursing through, the neighborhoods of Paddington, Belgravia and Chelsea could flourish. Nowadays, you can catch a glimpse of the river at Sloane Square Underground Station, where one of the pipes diverting the river is still visible.
4. The Wien River – Vienna, Austria
Visitors to Vienna often arrive expecting the illustrious Danube to roar into town, but it isn’t quite the massive river they envision. Instead, it basically babbles into the city and joins up with two other waterways that roll through the Austrian capital. One of them is the Donaukanal, which used to be the Danube’s main channel through the city until floods changed the river’s course and pushed it away from Vienna.
The other river flowing through Vienna is the Wien – also known as the Wein – which flows in from the west. Tourists can catch a glimpse if they visit the Schönbrunn Palace or stroll through the Stadtpark. After that, though, much of the city has been built over the river. It happened decades ago, and the underground channels divert the water flow into the city’s sewer system.
3. The River Frome – Bristol, England
The River Frome didn’t do much to endear itself to the citizens of Bristol. Instead, in the 1930s it breached its banks and destroyed parts of the city. And in 1968 a whopping five million gallons of water was pumped out of the city’s soccer stadium. Now, though, its ebbs and flows are much less noticeable.
The River Frome flows underneath a parking lot in the city’s center, and its banks are covered in trash. Still, some people have explored it by canoe. But the adventurers end up opening doors onto the city streets or popping their heads through manhole covers instead of mapping the underground river.
2. Tibbetts Brook – New York
It’s hard to imagine New York City as anything other than a concrete cityscape as far as the eye can see. Long before it developed into the metropolis of today, though, Native Americans roamed the lush lands. They centered their treks around nearby Tibbetts Brook, which was a one-time source of freshwater where hunters took advantage of the raccoons, birds, rabbits and muskrats in the area.
But Tibbets Brook didn’t remain a lush habitat for long. In the 1690s Jacobus Van Cortlandt had a dam built to create a lake on the stream. The city purchased his Bronx-based urban oasis in the 19th century – naming it Van Cortlandt Park. Eventually, the majority of the lake’s tributary ended up underground or full of toxins that wiped out thousands of fish in 1961.
1. The Cheonggyecheon – Seoul, South Korea
The tale of the Cheonggyecheon started like many of the others on this list. It once coursed through the heart of Seoul, but it gathered so much pollution that officials decided to use it as a drain instead of a source of freshwater. As a result, they buried it underground and built a freeway over it in the 1950s for good measure.
But the Cheonggyecheon’s story ends on a much happier note. In 2001 experts proposed restoring the river to its former glory, which meant removing the roadway to re-expose it. Surprisingly, their urban-renewal proposal would not only bring back freshwater to the heart of the city, but it would also improve traffic. So, the project got the green light, and now, locals can enjoy a 3.6-mile river and a surrounding park in the heart of their hometown.