Simplify the following text for a Grade 6 native English-speaking person.
Original: Limburg 's name derives from the fortified castle town known as Limbourg , situated on the river Vesdre in the Ardennes , now in the Walloon province of LiÃ ge .
Simplified: Limburg 's name comes from the fortified castle town known as Limbourg , located on the river Vesdre in the Ardennes . This is now the Walloon province of LiÃ ge .