The Space Needle is a tower in Seattle, Washington. It is at the Seattle Center. The Space Needle was built for the 1962 World's Fair. During this time, almost 20,000 people used the elevators every day. Over 2.3 million visitors came to the World Fair overall. The Space Needle is high and wide. It weighs 9,550 tons. When it was completed it was the tallest building to the west of the Mississippi River. It is built not to fall in wind up to and earthquakes of up to 9.1 magnitude. This gives protection against an earthquake as powerful as the 1700 Cascadia earthquake. The tower also has 25 lightning rods on its roof to protect it against lightning.