- Who
- Washington Monument
- What
- 169.3 metre(s)
- Where
- United States ()
At 169.3 m (555 ft 5 in) the Washington Monument in Washington DC, USA, is the tallest stone structure in the world that is constructed entirely without any steel reinforcement. Most modern buildings of any substantial height are built around a framework of steel-reinforced concrete to give then the necessary structure strength.