The tower is named after the number of floors it has - 101 above the ground (and five more underneath). It is shaped like eight stacked sections, each one a little wider at the top than at the bottom. From the side, it looks like a piece of bamboo, which is a plant that grows all across Taiwan. The bamboo shape is a quiet little joke: tall, strong and growing upwards.
Taiwan sits on top of a tricky piece of the Earth's crust where the ground sometimes shakes (this is called an earthquake) and where typhoon winds blow in from the sea. A regular tall tower would sway too much. So engineers built something amazing into Taipei 101: a giant golden ball that hangs near the top of the building.
The ball weighs 660 tonnes - as much as around 110 elephants. When the wind pushes the tower one way, the ball swings the other way, and the building stays still. Visitors can ride a lift up to the floor where the ball is and look right at it. It is the biggest 'tuned mass damper' in any building open to the public.
Up at the top, the lift that takes you there is one of the fastest in the world - it travels at 60 km/h, which is the speed of a car on a road. Your ears pop on the way up. From the observation floor you can spot mountains in the distance, the river that runs through Taipei, and the tiny shapes of people in the streets far below.