The Canadian National Vimy Memorial is its largest and principal overseas war memorial. Located on the highest point of the Vimy Ridge, the memorial is dedicated to the commemoration of the Battle of Vimy Ridge and Canadian Expeditionary Force members killed during the First World War and those killed in France during the First World War with no known grave. France granted Canada perpetual use of a section of land at Vimy Ridge in 1922 for a battlefield park and memorial. A portion of the former battlefield is preserved as part of the memorial park that surrounds the monument. The grounds of the site are still honeycombed with wartime tunnels, trenches, craters and unexploded munitions and are largely closed for public safety. A section of preserved trenches and a portion of a tunnel have been made accessible to visitors.