Osaka's landmark 40-storey building resembles a space-age Arc de Triomphe, twin towers connected at the top by a 'floating garden' observation deck. The 360-degree city views are breathtaking day or night, but getting there is half the fun: a see-through escalator tube takes you up the last five storeys with nothing but air between you and the ground. Not for the vertigo-prone, but for everyone else it's an architectural thrill designed by the same architect who created Kyoto Station.