Amsterdam's oldest surviving non-religious building, a squat medieval gatehouse sitting in the middle of the Nieuwmarkt square. Built in 1488 as a city gate (the Sint Anthoniespoort), it was converted into a public weigh house in the 17th century, where goods were weighed for tax purposes. The upper floors housed guild rooms, including the surgeons' guild anatomy theatre.
Over the centuries it has served as a fire station, a furniture warehouse, and a museum. The building now houses a restaurant and cultural space. Even if you don't go in, De Waag is a striking sight — a fairy-tale castle of turrets and gables stranded in the middle of a busy square, surrounded by market stalls and café terraces.