Windows on the World was a complex of venues on the top floors (106th and 107th) of the North Tower (Building One) of the original World Trade Center complex in Lower Manhattan that included a restaurant called Windows on the World, it operated until 2001 when they were destroyed in the September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda on which country?
September 11 attacks The September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda on the United States on the morning of Tuesday, September 11, 2001. The attacks killed 2,996 people, injured over 6,000 others, and caused at least $10 billion in infrastructure and property damage. 
December 11, 2007 Algiers bombings There were two near simultaneous bombings in Algiers which occurred on 11 December 2007 when two car bombs exploded 10 minutes apart starting at around 9:30 a.m. local time, in the Algerian capital Algiers. The al-Qaeda Organization in the Islamic Maghreb has claimed responsibility for the attacks, stating that it was "another successful conquest […] carried out by the Knights of the Faith with their blood in defense of the wounded nation of Islam." These attacks constitute another act of violence in the ongoing Islamic insurgency, a continuation of the Algerian Civil War that has claimed 200,000 lives.