The Waag (Waegh) is a former Weigh house in Haarlem that today serves as a café catering to tourists.

The building was designed by Lieven de Key around 1597 and is built with Namense steen from Namur, Belgium.

It is the only building in Haarlem that was built this way, and was designed in its day as a landmark that befits an authority.

The weigh house masters needed to be able to judge the correct measure of a shipload of grain that was delivered in Haarlem.

In 1821 the top floor of the Waag was rented to the artist club Kunst zij ons doel for drawing classes gathered around a live model.