Brussels exists as three overlapping entities: the City of Brussels municipality with approximately 180,000 residents, the Brussels-Capital Region comprising 19 municipalities with 1.2 million residents, and the metropolitan area extending to 2.6 million people. The Brussels-Capital Region occupies 161 square kilometers, making it one of Europe's smallest capital regions by area while containing the highest concentration of international institutions outside New York and Geneva. The city sits at 13 to 100 meters above sea level along the Senne River, which was vaulted underground between 1867 and 1871 and now flows entirely beneath the city center. Brussels functions as the de facto capital of the European Union, housing the European Commission, the Council of the European Union, and serves as one of two seats of the European Parliament alongside Strasbourg. NATO headquarters relocated from Paris to Brussels in 1967, establishing its current campus in Haren. The city operates as a bilingual region where both French and Dutch hold official status, though French dominates daily use with approximately 90 percent of residents speaking it as their primary or secondary language. Brussels lies geographically within Flemish Brabant but maintains political autonomy as Belgium's third region alongside Flanders and Wallonia.
The Grand Place measures 68 by 110 meters and stands as Brussels' central square, designated a UNESCO World Heritage Site in 1998. The Town Hall on the square's southwest side was constructed between 1401 and 1455, with its tower reaching 96 meters and topped by a five-meter statue of Saint Michael. Victor Hugo described the Grand Place in 1852 as "the most beautiful square in the world," though he was comparing it specifically to other European civic squares he had encountered during his exile. The square's guild halls were rebuilt between 1695 and 1700 after French artillery under Marshal de Villeroi destroyed the city center during a two-day bombardment. The Maison du Roi, despite its name, never housed royalty and has served since 1887 as the Brussels City Museum. The Grand Place hosts a flower carpet event every two years in August, covering the square's 3,750 square meters with approximately 500,000 begonias arranged in rotating designs. Markets occupied this site since the eleventh century, when Brussels was a fortified settlement on the trade route between Bruges and Cologne.
St. Michael and St. Gudula Cathedral sits 500 meters east of the Grand Place on Treurenberg Hill. Construction began in 1226 on the site of an eleventh-century chapel dedicated to St. Michael, with the structure reaching completion in 1500. The twin towers rise to 64 meters and were completed in the fifteenth century under architect Jan van Ruysbroeck, who also designed the Town Hall tower. The cathedral measures 108 meters in length with a nave width of 50 meters across the transept. Sixteen stained glass windows by Bernard van Orley were installed between 1537 and 1540, commissioned by Charles V and depicting members of the Habsburg family. The cathedral received its full designation in 1047 when St. Gudula's remains were transferred there—Gudula was a seventh-century Frankish noblewoman from Brabant who died around 680. Royal weddings have occurred here since the 1853 marriage of Leopold I's son, with most recent ceremonies including the 1999 wedding of Crown Prince Philippe and Mathilde d'Udekem d'Acoz. The building served as the co-cathedral of the Archdiocese of Mechelen-Brussels, created when Brussels became an archdiocese in 1559.
The Atomium stands in Heysel Park in northern Brussels, constructed for the 1958 Brussels World's Fair by engineer André Waterkeyn. The structure represents an iron crystal magnified 165 billion times, consisting of nine spheres each 18 meters in diameter connected by tubes containing escalators and corridors. The Atomium reaches 102 meters in height and weighs 2,400 metric tons, originally clad in aluminum that was replaced with stainless steel during a 2004-2006 renovation costing 26 million euros. Five of the nine spheres are accessible to visitors, with the top sphere offering views across Brussels from a restaurant 95 meters above ground. Approximately 600,000 people visit annually. The structure was designed to last six months but became a permanent landmark after the exposition, surviving multiple demolition proposals in the 1960s and 1970s. The world's fair attracted 42 million visitors over six months and introduced both the Atomium and the adjacent Heysel Plateau, which later hosted the 1985 European Cup Final where 39 people died when a wall collapsed at Heysel Stadium during crowd violence before the Liverpool-Juventus match.
The Royal Palace of Brussels occupies the eastern side of Place des Palais facing Brussels Park. The current palace facade was constructed between 1904 and 1912 under Leopold II, designed by Henri Maquet, though buildings have stood on this site since the Middle Ages. The Coudenberg Palace occupied this location from the twelfth century until a fire destroyed it in 1731, with the ruins excavated and opened to visitors in 1995 beneath the current palace and Place Royale. The Royal Palace measures 150 meters across its facade and functions as the administrative seat of the Belgian monarchy, though the royal family resides at Laeken Palace five kilometers north. Leopold II never saw the completed palace—he died in 1909 and construction finished three years later under Albert I. The Hall of Mirrors, completed in 1905, covers its ceiling with 1.4 million jewel beetle wing cases arranged by artist Jan Fabre in a 2002 installation. The palace opens to the public annually from late July through early September, the only period when the state rooms are accessible. The Belgian flag flies above the palace when the monarch is conducting official business inside, typically several days per week.
Manneken Pis stands at the corner of Rue de l'Étuve and Rue du Chêne, a bronze fountain sculpture of a urinating boy measuring 61 centimeters tall. Jérôme Duquesnoy the Elder cast the current statue in 1619, replacing earlier stone versions documented from the fifteenth century. The statue has been stolen repeatedly—French soldiers took it in 1747, returned after public pressure. A French ex-convict stole it in 1817, leading authorities to create multiple copies for security. The statue received its first costume in 1698 when Maximilian II Emanuel, Elector of Bavaria, donated a blue jacket and hat. The Manneken Pis wardrobe now contains over 1,000 costumes stored in a museum at the Maison du Roi, with the statue dressed for specific occasions including national holidays, foreign dignitary visits, and cultural celebrations. Cities and organizations worldwide send costumes, including an Elvis Presley outfit from the United States in 1998 and a Mozart costume from Austria in 2006. Various origin legends exist—saving the city by urinating on explosive fuses, a nobleman's lost son found while urinating—but no documentation confirms any specific origin story before the fifteenth century.
The European Quarter occupies approximately one square kilometer east of Brussels' historic center, centered on Schuman roundabout and Rue de la Loi. The Berlaymont building houses the European Commission headquarters, constructed between 1963 and 1967 and later closed from 1991 to 2004 for asbestos removal at a cost of 555 million euros. The building's distinctive X-shaped design rises 13 stories and measures 240,000 square meters of floor space. The Justus Lipsius building and Europa building house the Council of the European Union—the Europa building, nicknamed "The Egg," opened in 2017 with a design incorporating windows from demolished Résidence Palace. The European Parliament Brussels seat sits alongside Leopold Park, though Strasbourg hosts the parliament's monthly plenary sessions as required by treaty agreement that members have repeatedly challenged. Approximately 40,000 people work in the European Quarter institutions. The quarter's development required demolishing residential neighborhoods—the area called Quartier Léopold contained typical Brussels townhouses before institutional construction began in the 1960s, a process critics called "Brusselisation" to describe profit-driven demolition of architectural heritage.