Bossenstein Castle, Medieval castle in Broechem, Belgium.

Bossenstein Castle is a water castle in Broechem, built of red brick with horizontal bands of lighter stone above a stone base at the waterline. A tall octagonal tower with a dark conical roof stands at the left corner, beside a lower gated section with a small bridge. A long wing with a dark grey hipped roof and small dormers runs left to right, and a taller block with a steep dark roof and corner turrets rises behind. A central courtyard is surrounded by galleries.

The castle was founded in 1346 by Joannes van den Bossche and underwent major rebuilding in the 17th century. The eastern residential wing dates from the late 15th century, showing development across multiple periods.

The name Bossenstein comes from Joannes van den Bossche, recorded as owner in 1346; the castle was also called Halmaleshof or Allemanshof. The east wing was restored to its 17th- and 18th-century interior, keeping original materials, facades, roofs and joinery with their historic layers. The building is now a private house, and a golf and polo club, Bossenstein Golf en Polo Club, occupies the grounds around it.

The castle stands on the Bossenstein Golf and Polo Club course, so the grounds are given over to play and access around the building can be limited during matches or rounds. The moat, the brick bridge with its pointed and basket arches, and the keep are best seen from outside the course.

The original medieval tower of the castle connects to the late 15th-century wing through a system of covered galleries rarely noticed by visitors. This hidden link shows how the castle grew over centuries while preserving its core.