Hippodrome de Boitsfort is the old racecourse on the edge of the Sonian Forest, built in the late 19th century when Brussels' upper classes wanted a grand venue for horse racing. The surviving stands and open grounds make it a useful stop if you are exploring the forest side of the city rather than the historic centre.
Today the site is more about leisure, events, and green space than racing. It works best as part of a walk or cycle ride through the southern edge of Brussels.