Eclipse August 12, 2026 · Burgos / La Rioja, Spain
Will mountains block your eclipse view from Sierra de la Demanda?
Between Burgos and La Rioja, the Demanda range tops out at 2,271 m (San Lorenzo). Totality lasts a generous ~100 seconds here with the sun at ~7.8° — but the deep Najerilla and Oja valleys face the wrong way in places. Ridgetops and west-opening valley mouths are the picks.
The August 12, 2026 total solar eclipse over Sierra de la Demanda happens at very low sun altitude — under 10° in many places. At that altitude, even modest hills or ridges in your western horizon can block the sun completely. Every vantage point below has been pre-checked: we ray-cast the real terrain horizon from its exact coordinate and report whether the eclipsed sun clears the ridge line, with a link to the live 3D simulation to verify your own spot.
Each verdict is computed by ray-casting 360° from the exact coordinate over Mapbox Terrain-RGB elevation data (30 km range) — the same engine as the live 3D sky view. Margins under ~1° are flagged marginal: elevation pixels are ~75 m wide and can miss sharp ridge lines, and trees or buildings are not included.
Key viewpoints
Ezcaray Clear view at totality
42.325°N, -3.009°W
The sun clears the terrain by 3.4° at the critical moment. Terrain hides the sun at 20:49 — before the partial phase ends at 21:21.
Check terrain in 3D →Valdezcaray Blocked by terrain
42.240°N, -2.970°W
The terrain rises 13.9° above the sun — the eclipse is hidden behind the ridge from this spot. Terrain hides the sun at 19:33 — before the partial phase ends at 21:21.
Check terrain in 3D →San Millán de la Cogolla Blocked by terrain
42.326°N, -2.865°W
The terrain rises 6.4° above the sun — the eclipse is hidden behind the ridge from this spot. Terrain hides the sun at 19:59 — before the partial phase ends at 21:21.
Check terrain in 3D →Pradoluengo Clear view at totality
42.326°N, -3.205°W
The sun clears the terrain by 4.2° at the critical moment. Terrain hides the sun at 20:53 — before the partial phase ends at 21:21.
Check terrain in 3D →Anguiano Blocked by terrain
42.258°N, -2.770°W
The terrain rises 9.2° above the sun — the eclipse is hidden behind the ridge from this spot. Terrain hides the sun at 19:51 — before the partial phase ends at 21:21.
Check terrain in 3D →Drop a pin anywhere — Heliora computes the terrain horizon from that exact point and shows whether the eclipsed sun is visible above it.
Why does terrain matter so much?
- How low will the sun be during the eclipse?
- Across most of Spain the sun will be between 4° and 12° above the horizon at maximum eclipse. At 4°, a 100 m ridge half a kilometre away blocks the sun. At 8°, the same ridge needs to be 1.4 km away to clear it.
- How does Heliora know the actual horizon from my spot?
- Heliora downloads Mapbox Terrain-RGB elevation tiles around your pin and ray-casts 360° outward, sampling elevation every degree of azimuth and computing the apparent angle of the highest point. The result is the real local horizon from your exact GPS coordinate, not the flat-earth horizon.
- Does this work for buildings too?
- Yes — toggle the "buildings" layer in the sky view. Heliora pulls Mapbox 3D building data for the closest 2 km and renders them as occluders. This is critical in cities like Bilbao, Santander, or Madrid where city blocks can hide a low sun.
- Why did you build this?
- Generic eclipse tools tell you the sun's altitude but not whether your real horizon clears it. For a low-altitude eclipse like 2026-08-12 in Spain, that distinction is the difference between seeing totality and seeing nothing at all from a mountain valley.