Famous guard towers

• Alcatraz
  Alcatraz Island
  Alcatraz Island is an island located in the San Francisco Bay, offshore from San Francisco, California, United States. Often referred to as "The Rock" or simply "Traz", the small island was developed with facilities for a lighthouse, a military fortification, a military prison, and a Federal...
  
   guard towers
• Auschwitz II
  Auschwitz concentration camp
  Concentration camp Auschwitz was a network of Nazi concentration and extermination camps built and operated by the Third Reich in Polish areas annexed by Nazi Germany during World War II...
  
   guard towers
• Tower of London
  Tower of London
  Her Majesty's Royal Palace and Fortress, more commonly known as the Tower of London, is a historic castle on the north bank of the River Thames in central London, England. It lies within the London Borough of Tower Hamlets, separated from the eastern edge of the City of London by the open space...
  
  
• Yuma Territorial Prison
  Yuma Territorial Prison
  The Yuma Territorial Prison was a prison in the Arizona Territory of the United States and now in present day Yuma, Arizona. The Territorial Prison is one of the Yuma Crossing and Associated Sites on the National Register of Historic Places in the Yuma Crossing National Heritage Area.The site is...
  
  1876 guard tower.