The multi-turreted Waag was built as a gate in the city walls in 1488. In 1601 the walls were destroyed so that the city could expand, and the building was turned into Amsterdam's main weigh house, and later a spot for public executions. A bar-restaurant (open 9am to 10.30pm) occupies it today. Out the front, Nieuwmarkt square hosts a variety of events, including a Saturday farmers market and a Sunday antiques market.
In its early days the Waag looked more like a castle, fronted by a moatlike canal. By the 17th century it was home to various guilds. The surgeons' guild, which occupied the upper floor, commissioned Rembrandt's famous The Anatomy Lesson of Dr Tulp (displayed in the Mauritshuis museum in Den Haag). The masons' guild was based in the tower facing the Zeedijk; note the superfine brickwork.