The Willis tower

The Willis tower is located in Chicago, Illinois. Used to be known as the Sears Tower since built in 1973. This 108 story, 442m arquitectural building; used to be te tallest when built. It conserved this position as the tallest building for nearly 25 years. Now its the second tallest building in the US and the tenth tallest in the world. It was until 2009 when Willis Group Holdings bought the tower from United airlines and named it as now we know it, thw Willis Tower.



 The Willis tower is build up of 9 pillars, of diferent heights, givinng it's unique shape.
 

This is a view from Willis Tower's skideck. It has some glass squares that outstands out of the building making you step in glass and you have 180° of view, and you can look up or down, Right or left. Pretty amazing thing .