North Korea's Ryugyong Hotel is the world's tallest unoccupied building, according to Guinness World Records. The 105-storey pyramid-shaped skyscraper is 330 metre high. Construction of the building began in 1987 and took 25 years to be completed, after being halted on several occasions. Plans were made to open the hotel in 2012, and then in 2013, but were later cancelled.