manmade structures or places that have changed the world?

Question

looking for significant places in history in particular locations that have either been a turning point in history, or the modern day would not be the same without the occurance or events that happened at this or these locations...

Answer 1

1. Battle of Vienna, September 11-12, 1683
It brought about the decline in power of the Ottoman Empire in Europe, and allayed fears of muslim domination of Christian Europe.
http://en.wikipedia.org/wiki/Battle_of_Vienna

2. Sarajevo, June 28, 1914
The assassination of Archduke Franz Ferdinand of Austria led to the start of the First World War.
http://en.wikipedia.org/wiki/Assassination_of_Archduke_Ferdinand

3. Montgomery, December 1, 1955
The arrest of Rosa Parks led to the Montgomery Bus Boycott and the involvement of Martin Luther King in the civil rights movement.
http://en.wikipedia.org/wiki/Montgomery_bus_boycott

4. World Trade Center, New York City, September 11, 2001
The attacks on the World Trade Center led to the ongoing War on Terrorism.
http://en.wikipedia.org/wiki/9/11#The_War_on_Terrorism