Talk:Fort de Loyasse

Altimetry
In the lower right part of the entrance of the Fort Saint-Irénée there is engraved the number 380 preceded by a horizontal line placed one meter above the ground, it was thought to be the altitude in feet which had for a reference a rule located on the quay of the Saône, near the Bonaparte bridge.

The mode of calculation is difficult to understand as the number engraved on the entrance of Fort Loyasse (389) is more high than that of  Fort Saint-Irénée  (which has a plaque indicating 280m) to Loyasse's altitude of (271 m). A study by the ASSIL (SITES ASSOCIATION Loyasse) shows that the registered number is not in feet, but it is rather a negative altitude relative to the highest point of the area, calculated at 660m, corresponding perhaps to Fort Mont Verdun placed at 625m.

To back this up, other measures were taken by the members of this association with structures with an inscription of this type; the addition of engraved altitudes and identified through the IGN, either by the presence of a plate or from a plane always shows 660 m.