The world's tallest skyscraper, the Burj Khalifa, officially opened in Dubai on Monday in a blaze of fireworks. Rising 2,717 feet from the desert floor, the metal and glass spire is billed as a "vertical city" of luxury apartments and offices.

The tower also boasts four swimming pools, a private library and a hotel designed by Giorgio Armani. The Burj has more than 160 stories, the most of any building in the world, and an observation deck on its 124th floor. The Burj Khalifa will ultimately be the place of residence, work and leisure for up to 12,000 people.

Dubai officials hope the tower — which cost about $1.5 billion to build — will rekindle optimism in the Gulf Emirate, now undergoing a deep financial crisis.

Tickets to the observation deck are $27. The ride to the top takes just over a minute. www.burjdubai.com/.