De Waag is the remaining part of the original city walls in Amsterdam. Constructed as part of the fortification system, it originally served as one of the city gates. When the city walls were disassembled, a market square was created around it and weighing scales were placed inside the former gate. Hence its name -- the Scales House.

For a time, the upper floors of De Waag housed four guilds: smiths, masons, painters, and surgeons.in 1632, the surgeon guild commissioned Rembrandt van Rijn to paint its members at work; the resulting painting 'Anatomical Lesson of Dr. Tulp' became a sensation and made the young painter's name. After the dissolution of the guilds at the end of the 18th Century, De Waag served various purposes; for a period of time it housed a fire brigade and a museum. Today, it's taken care of by De Waag Society, created especially for this purpose.