UpToWhereSeeing far,
explained.
Guides and stories about line of sight, terrain visibility and everything you can (and cannot) see from a point on Earth.
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01August 13, 20269 min read
Total Solar Eclipse 2027: Where to Stand in Spain and Morocco
On 2 August 2027 totality crosses the Strait of Gibraltar. The centre line misses mainland Spain, so Tarifa gets 4m39s while Malaga gets 1m52s and Seville misses it entirely. Where the band falls, how long it lasts at your spot, and why the clocks jump two hours across 14 km of water.
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02July 26, 202684 min readEclipse 2026 Spain: Will You See It From Your Town?
A mountain hides the total eclipse from 28% of the path across Spain. Search your town for its computed verdict, or explore the 30 m terrain map.
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03July 24, 202615 min readThe Villages That Lose the Sun: We Computed Winter Darkness, Norway to the Alps
Rjukan, Viganella and a handful of Swiss villages are famous for spending months each winter in the shadow of a mountain. Nobody had ever put them on the same ruler. We ran a full year of terrain-corrected sunrises for thousands of settlements through 30 m elevation data, and found the ones nobody has named.
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04July 21, 202613 min readWhich Mountain Casts the Longest Shadow on Earth? We Computed All of Them
Tenerife says Teide casts the world's largest shadow. Everest fans assume the tallest peak must win. We ran a full year of sunrises and sunsets for twelve great mountains through 30 m terrain data. And the champion is in Alaska, the runner-up is in Iran, and Teide's real record is stranger than its own legend.
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05July 11, 20265 min readSolar Eclipse 2026 in Spain: Will a Mountain Block Your View?
The 2026 total eclipse happens at sunset, with the sun barely 10 degrees above Spain's western horizon. One ridge can hide the whole show. Type your spot for a free terrain verdict in seconds.
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06July 19, 202616 min readCan You Really See Mallorca From Barcelona? The Exact Geometry of a 190 km Sightline
Half of Barcelona refuses to believe the other half's photos. We computed every sightline from the city to Mallorca at full detail: 40,001 rays a pass, each walked end to end at 10 metres. Eleven Tramuntana summits clear the horizon, the minimum eye height is 93.85 m in a slot one tenth of a degree wide, Barcelona sees 0.62% of the island, and Mallorca, not the Pyrenees, is the farthest thing the city can see.
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07July 18, 202616 min readCan You Really See Seven States From Lookout Mountain? We Computed Every Sightline
Rock City has promised a view of seven states since 1932. We ran thousands of sightlines from across the whole mountain through 30 m elevation data, tested every state the marker names, and swept the refraction physics. Four states hold up: three from the marker itself, a fourth if you cross to the west brow. Three are impossible from anywhere up there.
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08July 13, 20266 min readHow Far Can You See From a Plane? The View From Every Altitude
We computed the view from 11,000 m above Barcelona: 668,689 km² of Earth in one glance, reaching Corsica 580 km away, a sightline that only exists because of refraction. The altitude ladder from eye level to the stratosphere, and how to check any window seat's view.
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09July 12, 20265 min readEarth's Curvature: How Much Does the Horizon Actually Hide?
The planet curves away at 7.8 cm per kilometre, and that tiny number hides entire skylines. The hidden-height formula explained with real cases: ships, Chicago across Lake Michigan, and mountains that peek over the bulge.
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10July 12, 20265 min readEclipse 2026: Spain's Best (and Worst) Mountain Viewpoints for Totality
On August 12, 2026 the total eclipse hangs just above Spain's WNW horizon, so the mountain you pick matters as much as the weather. The famous summits inside the band, ranked by their real western sightlines, and the beloved ones that miss it entirely.
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11July 12, 20264 min readFire Lookout Towers: The People Who Computed Viewsheds by Hand
A century before GIS, fire lookouts were placed by climbing peaks and sketching 'seen-area maps' by hand: viewshed analysis with a pencil. The story of how thousands of towers were sited, and how the same computation now takes seconds.
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12July 12, 20264 min readHow Far Can You Really See From the World's Observation Decks?
Every skyscraper deck claims '80 km on a clear day.' We computed the real terrain-limited sightlines: 263 km from the Burj Khalifa, 225 km from Tokyo Skytree, 151 km from the Empire State, and why haze means you'll rarely get either number.
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13July 12, 20264 min readBuying a Home for the View? Verify It Before You Sign
Sea and mountain views add 20–50% to property prices, and 'partial sea views' hide a thousand disappointments. How to verify exactly what a house, plot or specific floor will see, before you commit, with a free terrain analysis.
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14July 11, 20264 min readRadio Line of Sight: How to Check a Link Path Before You Build It
VHF, UHF and microwave links live and die by terrain. How to verify radio line of sight between two points (radio horizon, Fresnel zones, k-factor) with a free terrain analysis instead of guesswork.
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15July 11, 20264 min readDrone VLOS: Plan Your Flight So You Never Lose Sight (or Signal)
Visual line of sight is the law for most drone flights in the EU and US, and terrain breaks it faster than distance does. How to use a free viewshed analysis to pick launch points, spot terrain shadows and keep both eyes and radio on your drone.
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16July 11, 20265 min readThe Longest Lines of Sight on Earth: 400+ km With the Naked Eye
The world record for the longest photographed line of sight is 493 km: one mountain seen from another across an entire sea. Here are the greatest verified sightlines on Earth, and the physics that makes them possible.
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17July 11, 20266 min readHow Far Can the Human Eye See? The Real Answer, With Numbers
On a beach the human eye sees about 5 km to the horizon. From 100 m up, 36 km. From Everest, 336 km. What sets the limit (curvature, altitude, air), a calculator for your own height, and how to check the real answer from where you stand.
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