Pool of Peace, War memorial crater in Wijtschate, Belgium

The Pool of Peace is a water-filled shell crater near Wijtschate, in the Belgian municipality of Heuvelland, left by a massive underground mine explosion in World War I. The crater is now a pond surrounded by trees and reeds, sitting in the middle of a flat, open farming landscape.

On June 7, 1917, British forces detonated 19 mines simultaneously under German lines to break through near Wijtschate, in what became known as the Battle of Messines. The crater left behind by one of those blasts was never filled in, and over the following decades it gradually filled with groundwater.

The crater takes its name from the Spanbroekmolen, a mill that stood southwest of Wijtschate. Since 1992 it has been a protected monument, and the surrounding fields hold British military cemeteries such as Lone Tree Cemetery and Spanbroekmolen British Cemetery, which visitors can combine with the crater.

The site sits along a marked cycling route through the flat countryside of Heuvelland and is easy to reach by bike or on foot. Several other World War I memorials and sites are within a short distance, making it natural to combine this stop with others nearby.

Of the 24 mines planned for the Battle of Messines, one was neutralised by the Germans, one failed to explode and was set off by lightning on 17 July 1955, and three remain buried near The Birdcage. The Pool of Peace is the best-known of the 19 craters created on 7 June 1917.