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Saturday 25 July 2015

12 ASTOUNDING AQUEDUCTS


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12 Astounding Aqueducts
By Matt Hickman,
Mother Nature Network, 22 July 2015.

Architecture of conveyance

Aqueducts - usually monumental in size and architectural significance - carry water over natural and man-made obstacles: valleys, ravines, mountain passes, other bodies of water, even highways.

For many, aqueducts are most closely associated with the colossal arched edifices erected throughout the Roman Empire to provide burgeoning cities with fresh water sourced from mountain springs. Some of these soaring works of ancient infrastructure are still standing thousands of years later, a testament to Roman ingenuity. For others, the word aqueduct evokes the navigable, canal-carrying historic trough bridges found throughout the United Kingdom.

We've rounded up a dozen of the world's most distinctive aqueducts dating from the first century all the way through the last decade. Each is an impressive feat of civil engineering, like the Pont du Gard in France, seen here [top image].

1. Águas Livres aqueduct

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Photo: Pavel Arzhakov/Flickr

Between the 16th century watchtower, iconic suspension bridge, historic funicular (elevador) system, neo-Moorish bullring and enough soaring gothicedifices to delight even the most jaded European cathedral-hopper, Portugal's seven-hilled capital city of Lisbon is a veritable treasure trove of staggering feats of architecture and engineering spanning from the Middle Ages to modern day.

Impossible to miss is the Águas Livres aqueduct, a 36-mile marvel comprised of 109 formidable stone arches erected by order of King John V to bring much-needed fresh drinking water into Lisbon. Spanning the Alcantara Valley, Águas Livres miraculously survived the Great Lisbon Earthquake of 1755 with nary a scratch - the cataclysmic event all but levelled the vibrant port city in its entirety just a few short years after the aqueduct was completed. While decommissioned from service in 1967, the legacy of the aqueduct lives on thanks to the work of Museu da Água, an award-winning multi-site museum dedicated to preserving Lisbon’s historic water infrastructure. On a clear summer day, a guided tour across the aqueduct's view-heavy passeios dos arcos (walkways) is a much-recommended diversion (and a nice change of pace from the perpetually congested ramparts of Castelo de São Jorge). Just be sure to bring along a bottle of áqua.

2. Aqueduct of Segovia

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Photo: Frank Kovalchek/Flickr

If the ancient Spanish city of Segovia's 2,000-year-old namesake aqueduct doesn't scream "staggering feat of Roman engineering" then, honestly, we're not sure what will.

Joining a host of Romanesque churches, a storybook castle and one hell of a Gothic cathedral, Segovia's two-tiered aqueduct bridge all but dominates the skyline of Segovia's World Heritage Site-listed old city. Nearly 3,000 feet in length and a towering 94-feet-tall, the heraldic aqueduct - completion date circa A.D. 50 - is, after all, the only Segovia landmark to appear on the city's coat of arms. Composed of 167 monumental granite stone arches that march across the city, the mighty aqueduct, in regular use up until the late 19th century, is also the only Segovia landmark to be constructed overnight by an army of industrious demons under the employ of Old Scratch himself. The mystery-shrouded mythology surrounding this well-preserved work of infrastructure has earned it the nickname Puenta de Diablo - the Devil’s Bridge - as historians and archaeologists have been unable to credit the structure to a single person nor pin down an exact build date. Satanic back story aside, visitors should keep their eyes peeled for a statue of the Virgin of Fuencisla, patron saint and protector of Segovia, nestled within the upper arches of the immense edifice.

3. Aqueduct Ringvaart Haarlemmermeer

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In a low-lying nation best known for tolerance, tulips and a time-honoured tradition of manipulating the movement of water, you'd better believe the Netherlands has a doozy of an aqueduct.

However, it may come as a bit of a surprise that, in a country with such a knack for water engineering, the first aqueduct in the Netherlands wasn't completed until 1961 in the form of a water bridge carrying the circular Ringvaart Canal over both the A4 Motorway and an adjacent high-speed rail line. The whole concept seems completely improbable, fantastical even, if you think about it - just imagine zipping along on a highway through the countryside as a large river barge also chugs along directly above you. There have been several similar highway-spanning water bridges built across the Netherlands along the Ringvaart and other canals in recent decades including the world’s first so-called "naviduct," a navigable aqueduct/lock hybrid completed in 2003 near the harbour town of Enkhuizen in North Holland. This time-lapse video gives a decent glimpse of this impressive feat of engineering in action.

4. Barton Swing Aqueduct

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Photo: G-Man/Wikimedia Commons

While not all that impressive in the length, girth or aesthetics departments, this Victorian-era navigable aqueduct found in the Manchester suburb of Barton-upon-Irwell really, truly is in a league all its own.

Opened for boat traffic in 1894, the Barton Swing Aqueduct is the first - and only - swing aqueduct in the world. And by swing aqueduct, we mean that the Bridgewater Canal-carrying trough swings - pivots, really - open and shut at a 90-degree angle to accommodate large vessels passing below on the Manchester Ship Canal. As it swings open, a staggering 800 tons of water are retained within the aqueduct by gates on each end of the trough. When swung back into its "closed" position, the gates are released and boat traffic resumes on the Bridgewater Canal. The Barton Road Swing Bridge, a similar bridge that carries vehicular traffic instead of narrow boats, is located just upstream from this curious - and still very much operational - turn-of-the-century marvel. If the charming canals of North West England aren't in your future travel plans, this video, complete with rather stirring soundtrack, provides a decent glimpse of this singular aqueduct in action.

5. Carioca Aqueduct

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Photo: Wolfhardt & Klaus with K/Wikimedia Commons

Who ever said that a decommissioned aqueduct can't learn new tricks? A postcard-perfect landmark in a city chock full of postcard-perfect landmarks, Rio de Janeiro's Roman-style Aqueduto da Carioca (Carioca Aqueduct) stands as one of Latin America's most curious instances of historic adaptive reuse: a functional, 42-arch aqueduct bridge completed in 1750 that, nearly 150 years after it went into water-supplying service, was converted into a tramway bridge following a brief period of abandonment.

Incorporated into an extension of the fabled Santa Teresa streetcar trolley line (the bonde), the erstwhile aqueduct serves as the most scenic section of a tramway that carries passengers from Rio's city centre to the bohemian, hill-bound Santa Teresa neighbourhood. Largely a tourist attraction in recent years, the Santa Teresa Tram last made a trip across the Carioca Aqueduct in 2011, the same year the streetcar line was shuttered following a deadly derailment. (The accident, which claimed the lives of five people and injured many more, occurred on the winding cobblestone streets of Santa Teresa, not on the bridge itself). The 19th century tramway, outfitted with new streetcars currently being subjected to test runs, is slated to reopen to the public at some point later this year - just in time the 2016 Summer Olympics. This is fabulous news as Rio just isn't Rio without the bright yellow streetcars operating atop a colonial-era aqueduct.

6. Magdeburg Water Bridge

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Photo: WhiteDragon/Wikimedia Commons

When thinking of European aqueducts, we often think of the elegant and super-enduring arc bridges erected during the Roman Empire as a means of transporting fresh water to emerging settlements located largely in present-day Italy and on the Iberian Peninsula. In Germany, you'll also find the ruins of a Roman aqueduct in the form of Cologne's lengthy and largely underground Eiffel Aqueduct. However, when it comes to water bridges, it's a modern-day feat of engineering that rules the German aqueduct scene. And it's absolutely bananas.

Despite looking like an exceptional work of Photoshop trickery, the Magdeburg Water Bridge is indeed real. As for the science behind it, it's not all that complicated, really. Completed in 2003, the 112-foot wide navigable aqueduct can best be described as a freeway overpass for boats instead of cars; a river passing over a river; a "kilometre-long concrete bathtub." As the world's reigning longest navigable aqueduct (it spans over 3,000 feet), the half-billion euro Magdeburg Water Bridge links two vital shipping canals (Mittelland Canal and Elbe-Havel Canal) over the mighty River Elbe. Located within a bustling university town in Saxony-Anhalt that shares the same name, a visit to Germany's mind-blowing bridge for boats is a popular day trip from Berlin, which is an easy 90-minute drive from the northeast.

7. Mathur Aqueduct

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Photo: Infocaster/Wikimedia Commons

While a new-born compared to some of the centuries-old aqueduct bridges that appear on this list, the Mathur Aqueduct - also known as the Mathur Hanging Bridge - is a primo example of what happens when you fuse together civil engineering and tourism.

A high-traffic hotspot in southernmost India's tourist-y Kanyakumari District, the Pahrali River-spanning Marthur Aqueduct was completed in 1966. A hulking concrete structure supported by 28 massive pillars, the 1,250-foot-long bridge (reputedly, it's the longest aqueduct bridge in Asia and the tallest at 115-feet) still very much serves its original purpose: moving water for agricultural irrigation from heavily forested hill to heavily forested hill. The tourism part came into play later when carloads of visitors hailing from near and afar began ascending the steps up to the bridge’s walkway so that they could take in the knockout views from up top. (There’s a small fee to both park and access the aqueduct). While the lush tropical scenery from atop Mathur Aqueduct is unparalleled ("I was reminded of Jurassic Park while walking on this bridge," reflects one visitor), those who don't fair well with super-bumpy rural roads or suffer from acrophobia might want to take a pass and find another less, err, authentic diversion in and around Kanyakumari.

8. Old Croton Aqueduct / High Bridge

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Photo: H.L.I.T./Flickr

A marvel of engineering that enabled rather pungent 19th century Manhattanites to bathe under running water for the very first time, the gravity-fed Old Croton Aqueduct was a game-changer of the highest order when completed in 1842. Goodbye unsanitary conditions, hello showers and public swimming pools.

And while most of NYC’s early water distribution system travelled underground through a network of underground tubes along its 41-mile journey from then-bucolic Westchester County to the Big Apple, it emerged in a most spectacular fashion via Roman-style stone arch bridge at the point where the aqueduct crosses over the Harlem River from the Bronx and into Manhattan at Washington Heights. One part aqueduct bridge, one part pedestrian promenade, High Bridge (straddling the Harlem River at 123 feet, High Bridge lives up to its name) was a functional aqueduct bridge up until 1958; it remained open as a pedestrian footbridge until the early 1970s when it was shuttered following a period of prolonged period of neglect. In June 2015, a spiffed-up High Bridge - it's the oldest surviving bridge in New York City, by the way - reopened to pedestrian and bike traffic for the first time in over 40 years. In addition to sauntering along High Bridge’s community-connecting walkway, history buffs can also follow the route of the subterranean aqueduct along the Old Croton Aqueduct Trail.

9. Pontcysyllte Aqueduct

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Photo: Adrian Pingstone/Wikimedia Commons

From Wales, land of place names that are hard to pronounce and even more difficult to spell, comes Britain's longest (1,007 feet long) and highest (126 feet high) aqueduct - technically, a navigable water bridge that dates all the way back to 1805 when civil engineer Thomas Telford completed a magical cast-iron "stream in the sky" supported by 18 hollow mortar pillars made from lime, water and ox blood. Yes, ox blood.

Carrying the Llangollen Canal across the River Dee near the Welsh/English border, it costs a mere US$10 to embark on a dizzying 45-minute voyage across back and forth the historic span - a UNESCO World Heritage Site, by the way - via a 50-person narrow boat named Eirlys ("Snowdrop"). Or you can walk along the towpath. While a singular experience (aside from castle-hopping and attending male choral concerts, what else are you busy doing to in rural northeast Wales?) serious acrophobics may want to sit this one out. It's worth noting that Pontcysyllte ("Bridge that connects") isn’t the only navigable aqueduct along the Llangollen: Just a few miles downstream in the Ceiriog Valley, you'll find the daintier but easier-on-the-tongue Chirk Aqueduct, also designed by late 18th century infrastructure wizard, Thomas Telford.

10. Pont du Gard

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Photo: Andy Hay/Flickr

A dizzying feat of ancient hydraulic engineering, the Nîmes aqueduct originates at a freshwater mountain spring in Uzès and travels a total of 31 miles through what’s now the Languedoc-Rousillon region of southern France. For the most part, you wouldn't know that a super-old (we're talking built in the middle part of the first century) subterranean water tunnel is even there until the conduit emerges from underground and is carried across the Gardon River along the undisputed grande dame of Roman aqueduct bridges, the triple-span Pont du Gard.

While water stopped flowing along this monumental limestone arc bridge at some point during the 6th century, the 160-foot-tall structure - later used as a medieval toll bridge - remains an ingrained part of the landscape and a bona fide tour bus magnet that, as a centuries-old tourist attraction, ranks up there along the Eiffel Tower as one of France's most visited architectural landmarks. (It's the most visited ancient monument in the county). While never exactly low-key, the 1985 listing of Pont du Gard as a World Heritage Site only lead to the naturally stunning - and ecological sensitive - area around the bridge to become even more chaotic and congested. Recent improvements, however, have successfully mitigated the vehicular traffic and fairground atmospherics long-plaguing this remarkably preserved relic.

11. Querétaro Aqueduct

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Photo: Pabloangulo84/Wikimedia Commons

A Roman-style aqueduct in the middle of a Mexican metropolis? Sure, why not.

One of a small handful of Spanish colonial aqueduct bridges still standing in Mexico, the Aqueduct of Santiago de Querétaro is arguably the most photogenic. The 75-arched stone behemoth, which crosses over the Pan-American Highway at one point, supplied Querétaro’s capital city with drinking water well into the 20th century and, to this day, still supplies water to the fountains scattered about Querétaro's World Heritage Site-listed old city. Completed in 1738, legend has it that the aqueduct was commissioned by the Marquis del Villa del Alguia as a grandiose testament of his undying love for a beautiful - yet unattainable - woman named Clarissa. You see, Clarissa just happened to be a nun belonging to the convent of Santa Clara. With intimacy out of the question, the marquis believed that erecting a massive aqueduct would spiritually connect him with the off-limits object of his affection. Or something like that.

Querétaro’s tourism website analogizes the aqueduct in decidedly less romantic terms: "There is a snake crawling out of the centro histórico of Querétaro, Mexico. It makes its way 1.78 [kilometres] along what is now the avenue Zaragoza and finally hiding its head into one of the hills surrounding the centre of the city. This snake is over 30 meters tall, and is made of stone, its blood was the life’s blood of Santiago de Querétaro for centuries. This snake is the aqueduct of Querétaro."

12. Valens Aqueduct

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Photo: Brian Jeffery Beggerly/Flickr

The Grand Bazaar. The Blue Mosque. Galata Bridge. Topkapi Palace. Hagia Sophia. Overwhelming, immense and really old, Istanbul is one of those cities where you can diligently explore for days and days on end and still not see everything you set out to see. It's a city where you need to pace yourself - and arrive with a battle plan.

Visitors more keen on ancient works of infrastructure than houses of worship should place the magnificent Valens Aqueduct on the top of their must-visit list. Arguably the most iconic water-related structure next to the Basilica Cistern in the continent spanning Queen of Cities, Valens Aqueduct - Bozdoğan Kemeri in Turkish or "Aqueduct of the Grey Falcon" - is a real-deal Roman aqueduct commissioned by Emperor Valens in the late fourth century to supply water to then-Constantinople. While Constantinople itself has, ahem, changed hands a few times since the aqueduct's completion, what remains of it has been seamlessly integrated into the modern fabric of cat-ruled Istanbul. Nowhere else is the intersection of antiquity and modernity quite as dramatic (and literal) as the much-photographed point where the aqueduct's double-decker span soars above bustling Atatürk Boulevard with traffic passing right through the structure’s monumental limestone arches.

Top image: Pont du Gard, France. Credit: Wolfgang Staudt/Wikimedia Commons.

[Source: Mother Nature Network. Edited. Some links and images added.]

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