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The Bonhomme de Fer au Bois in Braine-le-Comte: an historical geodetic monument

  • Monument
  • Architectural heritage

This 30-metre-high tower was used by our ancestors with a network of 85 culminating points (including the Lion's Mound in Waterloo, the belfry in Mons...) to define in the 19th century, a map of Belgium using the triangulation system. It was later used to refine calculations for longitudes, latitudes, altitudes and gravity.

The geodetic monument, nicknamed the Bonhomme de fer or Tin man, can be found South of the Houssière forest.

The Bonhomme de fer principle

It was possible, from this tower, to see all a chosen selection of culminating points, the lion statue in Waterloo for example. Using trigonometry and ratios, an incredibly precise map, reaching accuracy of about one centimetre was created.

Guided tours

Guided tours are organised for local events (Heritage Days, nature walks, special hikes...). Brochures and trail maps are available from the Tourist Office in Braine-Le-Comte.

The information provided is an indication only. We advise you to inquire directly with the organisers of the event that interests you before you leave.