Camouflage trees like this one was used to spy on the enemy during the First World War.

(This was 9th most liked picture on the History Season Instagram page this year)

These trees were also armored to protect the observer from enemy fire. They were invented by the French but were used extensively by both sides during the war.

The construction process began with a military artist identifying a tree in no man’s land. The artist would then take photographs, make detailed measurements, and draw sketches of the tree.

This information was taken to a workshop, where a team of artists created an exact replica out of iron. At nighttime, under the cover of total darkness, the original tree was cut down, and the metal replica was installed without anyone noticing.

Trees like these were employed by both sides of the conflict.

Sources: Imperial War Museum and Smithsonian Magazine