Louvain

An old market street in Louvain. 

(Credits: public domain)

Liège

Searching on the Wikimedia Commons I found these two pictures of 17th century Liège. 

 Liège in 1649. From the Novum ac Magnum Theatrum Urbium Belgicae, by J. Blaeu, published in Amsterdam in 1649.

A view of the city ca. 1650, from an engraving by Matthäus Merian published in Frankfurt.

Bruges

An old street in Bruges (Brugge in Dutch), the capital of the province of West Flanders, Belgium. The Church of Our Lady is in the background. 

Photo credits and licensing information here.