The Cinquantenaire is a large urban park located in the eastern part of Brussels, Belgium. The park was created in 1880 for the 50th anniversary of Belgian independence, and is home to several museums, monuments, and green spaces.

The centerpiece of the park is the Arcades du Cinquantenaire, a large triumphal arch that was built to commemorate the anniversary of Belgian independence. The arch is made of white stone and features three archways, each adorned with a sculpted group of figures representing the various provinces of Belgium.

The Cinquantenaire also houses several museums, including the Royal Museum of the Armed Forces and Military History, the Royal Museums of Art and History, and Autoworld, which showcases vintage and classic cars.

The park itself is a popular destination for locals and tourists alike, offering ample space for walking, jogging, and picnicking. It features expansive lawns, tree-lined avenues, and a large pond, which is often used for boating and fishing.