Terrain visibility analysis

Can you see Mont Blanc from Annecy?

Short answer: No, not from this exact point in central Annecy. Terrain about 4.6 km away cuts the line of sight towards the summit.

Mont Blanc is 57.6 km away, almost due east. But from this exact point in central Annecy, closer terrain stands in front of it and hides the summit.

View the calculation in Sightelo

Key figures

Observation point: Annecy city centre, France
Point of interest: Mont Blanc, France/Italy
Target elevation: 4,807.3 m
Straight-line distance: 57.6 km
Direction to the summit: 97.1° (east)
Blocking terrain at: 4.6 km

Terrain profile and line of sight

Detailed profile

Scroll horizontally to explore the full profile on a small screen.

Calculated terrain
Observer–summit sight line
Minimum visibility line
0 m reference (modelled curvature)

Terrain already includes modelled curvature and refraction (k = 0.13). The grey curve is the 0 m reference: subtract it from the terrain curve to read real elevation. Sight lines remain straight; no second curvature correction is applied. Vertical and horizontal scales differ.

The calculated obstacle is 4.5929 km from A. It rises 417.8 m above the sight line locally; the projected deficit at the summit is 5240.8 m. These are different quantities.

The calculation models terrain, Earth curvature and standard atmospheric refraction. It does not model buildings, trees, clouds, haze or local atmospheric variations.

Minimum line off scale — Nearby terrain requires a minimum target altitude of 10048.1 m, above the summit's actual 4807.3 m. The minimum visibility line continues beyond the chart without changing its slope.

Calculated profile values

Distance (km)	57.6 km
Observer eye altitude	452.5 m
Summit altitude	4807.3 m
Minimum visible target altitude	10048.1 m
Target margin above the modelled horizon	-5240.8 m
Minimum local sight-line clearance	-417.8 m
Displayed / calculated samples	500 / 578
Excluded around A / B	200 m / 1500 m
Blocking obstacle	4.5929 km

Audited calculation: 2026-10-13. The interactive calculator can recalculate with currently available elevation data.

Why is the view blocked?

About 4.6 km from the starting point, the terrain reaches roughly 1,201 m in elevation. It crosses the line between the observer and the Mont Blanc summit. This terrain therefore sits in the field of view.

Would the answer be the same everywhere in Annecy?

Not necessarily. The calculation applies only to the point shown and to an eye height of 1.7 m above the ground. Moving elsewhere or gaining height can change where this nearby terrain sits in the view. Buildings, trees, haze and clouds are not included.

Technical details

Observation point coordinates: 45.899247, 6.129384
Summit coordinates: 45.832706, 6.865171
Terrain model: Copernicus DEM 90
Eye height: 1.7 m
Refraction used: Standard (k = 0.13)