Alvaux Tower, locally known as Tour d'Alvaux or Alvau, stands in the village of Nil-Saint-Vincent, south of the city of Brussels in Belgium.
Alvaux Tower is a tower house built between 1183 and 1217 by Arnould II de Walhain. The land was yielded to him by Berthe; the abbess of Nijvel (or Nivelles in French) in 1199. The seigniory of Alvaux depended on Walhain Castle and had connections with the nearby Griffon du Bois Tower.
When it was built it was surrounded by ditches and equipped with a drawbridge. On top there would have been a pyramidal roof. With this roof the tower would have been some 20 meters high.
Today the tower is situated on a camping ground; the camping d'Alvau. The caravans stand right beside it. Access to the tower is prohibited.