Donjon Ter Heyden, Medieval fortified tower in Rotselaar, Belgium.

Donjon Ter Heyden is a 30-metre brick keep built between 1350 and 1363 for Gerard van der Heyden, bailiff of Brabant. It stands on a white sandstone base, rises through six storeys on a Greek-cross plan, and is surrounded by a moat. A pear-shaped spire and slate roof were added in the 17th century; the white and ferruginous sandstone facing dates from 1870.

Gerard van der Heyden, a bailiff who gained noble rank through marriage, ordered the tower's construction between 1350 and 1363. It was built during a period when landowners erected such fortifications to secure their power and protect their territories.

The tower's floor plan follows a Greek cross shape, showing how medieval defenders thought about protecting themselves. This unusual design allowed those inside to watch multiple directions at the same time.

The tower stands at the corner of Terheidelaan and Torenhoflaan, northeast of Rotselaar's village centre, surrounded by moats and reached by a wooden footbridge from the 17th-century manor. It is a private residence, so visits are limited to heritage open days; the roof restoration funded in 2026 may restrict access. The chimney of the former De Toren brewery stands beside it.

An industrial chimney from a former brewery stands right beside the medieval tower, marking where beer production continued until 1939. This unusual pairing shows how the site transformed from a defensive stronghold into an industrial workplace.