The Most Beautiful Reservoirs in the World

13 places in 10 countries · updated 13 October 2026

1. 01 Lake of Sainte-Croix

   Lac de Sainte-Croix

   France43.764° N 6.184° E

   

   The Lake of Sainte-Croix is what happens when the Verdon, having carved one of Europe's deepest river canyons, spills out into open country. At the Pont du Galetas the limestone walls of the Gorges du Verdon suddenly part and the river widens into a sheet of startlingly milky turquoise water, framed by dry garrigue hills and the villages of Upper Provence. It is not a natural lake: the reservoir was created by a concrete arch dam 94 metres high, built between 1971 and 1974 by Électricité de France, and the valley was flooded in 1973.

   Did you know? Georges Clemenceau, then France's prime minister, toured the length of the Verdon on donkeyback in 1908, when damming the river was already being discussed.

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2. 02 Lake Powell

   United States36.936° N 111.484° W

   

   Lake Powell is a flooded labyrinth. When the Glen Canyon Dam closed the Colorado River near the Arizona–Utah line in 1963, water began backing up into Glen Canyon and more than ninety side canyons, turning a maze of Navajo, Wingate and Kayenta sandstone into a reservoir some 186 miles long with a shoreline of about 3,000 kilometres. Construction of the dam had begun in 1956; it was dedicated in 1966, and the lake was named after John Wesley Powell, the Civil War veteran who explored the river in wooden boats in 1869.

   Did you know? When full, the lake holds over 24 million acre-feet of water, second in the United States only to Lake Mead downstream.

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3. 03 Basilica Cistern

   Yerebatan Sarnıcı

   Turkey · 1.1 km from Istanbul41.008° N 28.978° E

   

   The Basilica Cistern is a drowned forest of stone under the streets of Istanbul's old city. Emperor Justinian I had it built in the 6th century on the site of a great Roman-era basilica — hence its name; in Turkish it is Yerebatan Sarnıcı or Yerebatan Sarayı, the "sunken palace". The vault, about 138 by 65 m, rests on 336 marble columns, each about 9 m high, set in twelve rows of twenty-eight and spaced five metres apart. When full, the reservoir held up to 80,000 m³ of water, brought some 19 km from the Belgrad Forest north of the city along a chain of aqueducts that included the Valens Aqueduct.

   Did you know? Before the walkways were built in the 1980s, visitors toured the cistern by rowing boat, gliding between the columns over the water.

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4. 04 Diablo Lake

   United States48.714° N 121.131° W

   

   Diablo Lake is the most vividly coloured stretch of water in the North Cascades: a reservoir on the upper Skagit River in Washington whose surface glows a milky turquoise against dark forest and grey granite. The colour comes from the glaciers high on the surrounding peaks. As they grind over bedrock they produce a fine powder known as glacial flour, and meltwater streams carry it into the lake, where the suspended particles scatter sunlight. The effect is strongest on bright days in high summer, when melting is at its peak.

   Did you know? Diablo Dam held the title of world's tallest dam only briefly, until Oregon's Owyhee Dam was completed in 1932.

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5. 05 Abraham Lake

   Canada52.224° N 116.427° W

   

   Abraham Lake is a reminder that a reservoir can be as striking as any glacial lake. It came into being in 1972, when the Bighorn Dam, built by what was then the Calgary Power Company, held back the North Saskatchewan River on the front ranges of the Canadian Rockies. The water spread along the valley for about 32 km, a narrow ribbon rarely more than three kilometres wide, at roughly 1,340 m above sea level. Although the lake is artificial, it takes its milky turquoise colour from the same fine rock flour that tints the glacier-fed lakes of Banff and Jasper, carried down by the river from the icefields upstream.

   Did you know? Covering about 54 square kilometres, Abraham Lake is described as Alberta's largest reservoir.

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6. 06 Piscina Mirabilis

   Piscina mirabilis

   Italy · 14.7 km from Naples40.795° N 14.080° E

   

   Under a hill above the town of Bacoli, on the western tip of the Bay of Naples, lies a vast underground hall built not for people but for water. Forty-eight cruciform pillars, in four rows of twelve, hold up barrel vaults some fifteen metres high, dividing the space into five long aisles like the nave of a church; light falling through openings in the roof cuts slanting beams through the dim interior. Locals call it the Cathedral of Water. The Piscina Mirabilis, the "wondrous pool", a name traditionally attributed to Petrarch after one of his visits, is one of the largest cisterns the Romans ever built.

   Did you know? The cistern was a terminus of the Aqua Augusta, a network about 145 km long with its branches, among the longest aqueduct systems in the Roman world.

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7. 07 Lake Koman

   Liqeni i Komanit

   Albania · 20.6 km from Pukë42.219° N 19.899° E

   

   Lake Koman looks less like a reservoir than a fjord that has wandered south into the Albanian Alps. For much of its length the water fills a narrow valley completely, hemmed in by forested hills and sheer rock walls, and at its tightest gorge the vertical cliffs stand only a little more than fifty metres apart. The surface is a deep, still green, and the shoreline offers almost nothing flat: slopes drop straight into the lake, and the only sign of settlement is the occasional farmstead clinging above the waterline.

   Did you know? One of the lake's boats, the Dragobia, has been sailing since 1994 with a cabin made from an old bus set on a ship's hull.

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8. 08 Cheow Lan Lake

   Thailand9.000° N 98.767° E

   

   Chiao Lan Lake, also written Cheow Lan, is a reservoir in the heart of southern Thailand, created when the Ratchaprapha Dam closed the valley of the Khlong Saeng in the 1980s. The name of the dam was given by King Bhumibol Adulyadej and means "light of the kingdom". What the rising water left behind is one of the most theatrical landscapes in the country: sheer limestone pinnacles and walls, cloaked in jungle, standing straight out of green water across more than 160 square kilometres. Thais often call it a Guilin of their own, and the comparison is fair.

   Did you know? As the valley flooded, conservationist Seub Nakhasathien led Thailand's first large wildlife rescue, capturing 1,364 animals of 116 species over eighteen months.

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9. 09 Reschensee

   Lago di Resia

   Italy46.801° N 10.531° E

   

   In the 1920s the Italian company Montecatini began planning a hydroelectric reservoir in this high Alpine valley, and by the time the dam was finished, in 1949, the project had merged two natural lakes and drowned the villages of Graun and part of Resia. The waters rose in 1950, swallowing 163 homes and, with them, the parish church of Curon. Locals fought the plan for years — petitions, appeals to Rome, a decade of delay — but the reservoir went ahead anyway, and the valley's older village disappeared beneath it for good.

   Did you know? At about 1,498 metres above sea level, it is described as the largest lake above 1,000 metres in the Alps.

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10. 10 Portuguese cistern

    Morocco · 0.8 km from El Jadida33.257° N 8.503° W

    

    A single round opening in a vaulted stone ceiling lets one column of daylight drop into a dim, square hall, and a thin sheet of water on the floor turns the pillars, ribs and arches into a perfect upside-down reflection that trembles whenever a drop falls. The Portuguese Cistern lies beneath the old citadel of El Jadida, the fortified town on Morocco's Atlantic coast that the Portuguese knew as Mazagan, and it is one of the most quietly theatrical interiors anywhere on the shores of Africa.

    Did you know? Accounts say the forgotten cistern was rediscovered in 1916 by a local shopkeeper who broke through a wall while enlarging his premises.

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11. 11 Peñol–Guatapé Reservoir

    Embalse Peñol-Guatapé

    Colombia6.261° N 75.190° W

    

    The Peñol–Guatapé reservoir is a landscape made by flooding, and it shows. When Empresas Públicas de Medellín dammed the Nare River in eastern Antioquia in two stages, finished in 1972 and 1979, the water did not fill a single basin but crept into dozens of valleys among steep green hills. The result is a maze of inlets, peninsulas and wooded islands spread over about 74 km², the largest body of water in the department, with a shoreline so convoluted that from above it looks less like a lake than like a flooded map. The reservoir feeds a hydroelectric system of some 560 MW and is the most heavily regulated in Colombia.

    Did you know? The water drops through a pressure tunnel to a cavern power station about 400 metres underground, five kilometres east of the lake, with a head of some 810 metres.

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12. 12 Covão dos Conchos

    Portugal · 13 km from Covilhã40.364° N 7.611° W

    

    High in the Serra da Estrela, at around 1,500 metres, a small mountain lake drains into what looks like a hole in the surface of the water. Covão dos Conchos is an artificial lake, and its centrepiece is a perfectly round bell-mouth spillway: a stone funnel rising from the lake into which the water pours from every side at once, vanishing into the ground as if down a giant plughole. Around it lies the bare, boulder-strewn granite plateau typical of Portugal's highest mountain range.

    Did you know? The small dam that forms the lake is built of concrete and granite and holds a useful storage of only about 120,000 cubic metres.

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13. 13 Caddo Lake

    United States · 32.4 km from Shreveport32.710° N 94.010° W

    

    There are two competing stories for how Caddo Lake came to exist, and they disagree about almost everything except the outcome. The Caddo people's own account holds that the Great Spirit caused a sudden earthquake to punish a disobedient chief, and the lake appeared more or less overnight, around 1811 — the same period as the real, well-documented New Madrid earthquakes. The geological account is far slower and less dramatic: a natural log dam called the Great Raft had been building up on the Red River since the 1600s, fallen trees accumulating year after year during spring floods, until sometime in the early 1800s the jam finally blocked the river enough to push water sideways into the Cypress Valley — flooding a forest gradually rather than instantly, and leaving the lake behind as the water settled.

    Did you know? The world's first over-water oil platform, Ferry Lake No. 1, was completed on Caddo Lake in 1911 by the Gulf Refining Company.

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