Daredevil: A tightrope walker practises between two spheres of the Atomium monument in Brussels, Belgium earlier today
Such great heights: The Belgian and French acrobats walked between the steel spheres 300 feet in the air
Don't look down: The Atomium offers spectacular views of the city from its nine spheres
The Atomium, which stands 335 feet tall, was built in 1958 when Belgium's capital hosted the World's Fair. The nine steel spheres have viewing holes offering visitors sights of the city.
The tubes between the spheres contain escalators allowing tourists to travel between the balls and see Brussels from different angles.
Balance: The tightrope walkers had to exercise incredible poise to stay upright against the wind
Ta-da! The acrobats had only a small harness around their waists to prevent a fall to the ground, but their balance prevented them from needing it
Monument: The Atomium was built in 1958 for the World's Fair in Brussels. The aluminium panels, left, were replaced in 2004
The monument had to be renovated in 2004, with the faded aluminium panels on the spheres replaced with stainless steel ones.
The design of the building mimics the atomic shape of an iron crystal magnified 165 billion times. The monument features in Pink Floyd's 1968 video for their song Paint Box.
Poise: The barefoot tightrope-walkers need incredible strength and concentration to stay upright
