The name Heysel comes from the Old Dutch heizel, meaning meager pasture or hill - a fitting label for a piece of land that for most of its history grew thin grass and supplied building stone. The Affligem fathers held the area in the Middle Ages. Quarries cut from its slopes built the Jesuit Church in Antwerp and the Church of Our Lady of Finisterrae in central Brussels, and the depressions left behind still ripple through Osseghem Park. Two hamlets perched on the plateau - Verregat to the north and Osseghem to the south, near where the King Baudouin Stadium now stands - and Wednesday markets and pilgrimages to the Chapel of St. Anna's miraculous spring drew villagers from the surrounding countryside. None of it suggested what was coming. When the City of Brussels annexed Laeken in 1921 and acquired the former royal lands of Leopold II, the city planners looked at the empty heights and saw something the farmers never could: a stage large enough for a world's fair.

Belgium turned one hundred in 1930, and Brussels marked the centenary by laying out an entire neighborhood. The Centenary Palace, designed by the architect Joseph Van Neck, was meant to crown the new exhibition grounds. The Jubilee Stadium - later renamed Heysel, later King Baudouin - rose at the southern edge of the plateau, ready to host the celebrations of the Belgian Revolution. The actual world's fair waited until 1935, when the Brussels International Exposition opened in the just-finished palace. It drew twenty million visitors. The Centenary Palace survived to become Brussels Expo, which now stretches across twelve halls and 22 hectares - the largest exhibition space in the Benelux, and the place where Eurovision came in 1987 and where Brussels still mounts every show that needs a roof.

The 1958 fair was different. Expo 58 was the first general world exposition since the war, and the world that turned up was not the same world that had visited Paris in 1937. Visitors walked from the Soviet pavilion to the American pavilion across a few hundred meters of Heysel ground; the United States had hired the architect Edward Durell Stone, the Soviets brought a full-scale model of Sputnik. Le Corbusier designed the Philips Pavilion - a tent-like hyperbolic concrete shell that hosted a multimedia piece by Iannis Xenakis and Edgard Varese, and was dynamited in 1970 when no one could figure out what to do with it. Above all of it stood the Atomium, originally planned to be temporary, devoted in its first incarnation to the peaceful uses of atomic energy. The fair closed; nearly every pavilion came down. The Atomium stayed. The unit cell of an iron crystal, blown up to the size of a building, turned out to be the one piece of futurism Brussels could not bring itself to dismantle.

Heysel Stadium had been built in 1930 for a celebration, and by 1985 it was 55 years old and failing. On May 29 of that year, the European Cup final between Liverpool and Juventus drew 60,000 supporters to the plateau. An hour before kickoff, a retaining wall in Section Z collapsed under the crush of fans fleeing violence from the neighboring terrace. Thirty-nine people died, most of them Italian. Officials, fearing further chaos, ordered the match played anyway. Juventus won 1-0 on a Michel Platini penalty in a stadium where ambulances were still arriving and bodies still lay on the grass. The disaster transformed European football - English clubs were banned from continental competition for five years - and it ended the old stadium. Heysel was rebuilt and renamed King Baudouin Stadium in 1995, the renovation completed on the same footprint, but the wall that gave way, and the people who died against it, are commemorated by a plaque on the site. The plateau where Belgium once advertised the future is also the plateau where 39 supporters never made it home.

Today the Heysel still works as a stage. The Atomium has been re-skinned in fresh aluminum and turned into a museum of itself, its spheres open to visitors who climb internal staircases between the atoms of an imagined crystal. Mini-Europe sprawls beside it - a miniature park where the great monuments of the continent stand at one-twenty-fifth scale, and where a small Atomium poses next to a tiny Eiffel Tower in cheerful disregard of proportion. The Kinepolis cinema, the planetarium of the Royal Observatory, the Palais 12 concert arena, the design museum named ADAM that occupies the old Brussels Trademart all share the grounds. The Heysel/Heizel metro station, opened in 1985, brings visitors directly to the foot of the spheres. The plateau is still trying to be a window onto the world. A planned European Union quarter here was scaled back in 2020, but the broader Neo redevelopment continues. The Atomium - built to last six months, still standing after sixty-seven years - sets the tone.