During 2004 the construction work finished on what was the tallest building in the world. In which city is this building?

Taipei 101 formerly known as the Taipei World Financial Center – is a landmark supertall skyscraper in Xinyi District, Taipei, Taiwan. The building was officially classified as the world's tallest in 2004, and remained such until the completion of Burj Khalifa in Dubai in 2009. In 2011, the building was awarded the LEED platinum certification, the highest award according to the Leadership in Energy and Environmental Design (LEED) rating system, and became the tallest and largest green building in the world.

Construction on the 101-story tower started in 1999 and finished in 2004. The tower has served as an icon of modern Taiwan ever since its opening. The building was architecturally created as a symbol of the evolution of technology and Asian tradition. Its postmodernist approach to style incorporates traditional design elements and gives them modern treatments. The tower is designed to withstand typhoons and earthquakes.