's Gravenkasteel, Medieval castle in Grimbergen, Belgium

's Gravenkasteel is a water castle in Humbeek, north of Grimbergen, on the edge of the 's Gravenbos. It is built of brick and sandstone, with the oldest parts dating from the 15th and 16th centuries. The red-brick facade has a square tower with a steep pointed roof, a conical-roofed turret, a stepped gable, and a taller rounded tower with a domed roof at the right end.

The castle's origins lie in the 14th century, with the oldest parts dating from the 15th and 16th centuries. It suffered heavily from war at the end of the 16th century and was repaired in the 17th century. In the 19th century it was restored and expanded in a neo-traditional style. Around 1700, castle lord Jacques Le Cocq became a count in Castile, making Humbeek a county.

The castle is also called Kasteel van Humbeek or Lundenkasteel, after the Antwerp family Lunden that owned it from 1880. Baron Theophile Lunden, lord of the castle until 1908, was a general of the Jagers te Paard and grand equerry to the royal family; the Lundens long kept a stud of thoroughbred horses at Humbeek.

The castle park, with its two monumental cedars, is closed to the public. The surrounding 's Gravenbos is open on its footpaths, including Buurtweg 17 and 30 and Voetwegen 63 and 64. The GR128 long-distance route from Pas de Calais to Aachen crosses the 100-hectare estate.

The castle park, with two monumental cedars, is closed to the public, but the surrounding 's Gravenbos is open on its footpaths, including Buurtweg 17 and 30 and Voetwegen 63 and 64. The GR128 long-distance route from Pas de Calais to Aachen crosses the 100-hectare estate. The Lebanon cedar and atlas cedar were protected as monuments in 2010; the Lebanon cedar may date from the 1860s, while the atlas cedar was planted after 1880.