 Vlaardingen's town archaeologist Tim de Ridder suggests the church hill in the centre of Vlaardingen as the most obvious place for Dirk III's castle.From this spot one has a view over the Merwede, the port, the count's farmstead and the surrounding area, making it a strategic position.In 2007, ground radar and tracer investigations on the church hill revealed a circular shape, a few metres below the church floor, with a diameter of 27 metres.