The observation deck on the Burj Khalifa in Dubai, the tallest building in the world, has been closed for repairs only a month after it opened.
Emaar Properties, the builder of the tower, said there had been an unexpectedly high number of visitors and problems with the power supply.
Visitors to the tower pay US $100 (UK £64) to visit the viewing deck or, if they pay in advance, about US $30.
It is not known when the viewing platform will reopen.
Dubai opened the tower on 4 January in a blaze of fireworks.
The building, which had been known as Burj Dubai, was renamed Burj Khalifa in honour the ruler of neighbouring Abu Dhabi.
Construction of the tower began in 2004. It stands at 828m (2,716ft) high.
Clad in 28,000 glass panels, the tower has 160 floors and more than 500,000 sq m of space for offices and flats.
The tower also lays claim to the highest occupied floor, the tallest service lift, and the world's highest observation deck - on the 124th floor.