The Atomium is a monument built for Expo '58, the 1958 Brussels World's Fair. Designed by André Waterkeyn, it is 103-metre (335-feet) tall, with nine steel spheres connected so that the whole forms the shape of a unit cell of an iron crystal magnified 165 billion times. Tubes which connect the spheres along the 12 edges of the cube and from all eight vertices to the centre; these tubes enclose escalators containing exhibit halls and other public spaces; the top sphere provides a panoramic view of Brussels. The spheres are 18 metres in diameter; three upper spheres lacking vertical support are not open to the public for safety reasons. The Atomium is located at [show location on an interactive map] 50°53′41″N 4°20′28″E / 50.89472, 4.34111Coordinates: [show location on an interactive map] 50°53′41″N 4°20′28″E / 50.89472, 4.34111, beside the King Baudouin Stadium in Heysel Park. Just next to it lies the Mini-Europe park and the Heysel/Heizel metro station.