This is commonly called the Brooding Soldier:-

Sited on Vancouver Corner about a mile south-east of Langemark-Poelkapelle near Saint-Julien (Sint-Juliaan in Flemish,) it marks the spot where the first large-scale gas attack on the Western Front was launched by the Germans on 22^nd April 1915. It sits in a beautifully kept memorial garden. The trees are apparently deliberately trimmed into the shape of artillery shells.

View from within the gardens:-

Closer view:-

Head detail. Stunning:-