The Sinimäe Hills (Sinimäed) are historically significant high ground in Ida-Viru where some of the fiercest fighting in Estonia took place during World War II, particularly in the summer of 1944 along the Tannenberg Line. The Sinimäed battlefield memorial, completed in 1999 near Grenadier Hill, honours all soldiers who fell in these battles. Its central feature is a 12-metre steel cross with a symbolic composition representing an explosion. 

Originally intended as a neutral place of remembrance for those who fought on different sides, the memorial later gained additional plaques remembering specific units. Nearby, the Vaivara Sinimäe Museum offers exhibitions of weapons, uniforms and personal items from the 1944 battles, helping visitors connect with the human stories behind the historic events.