The Waag (weigh house) is a 15th-century building on Nieuwmarkt square in Amsterdam.
It was originally a city gate and part of the walls of Amsterdam. The building has also served as a guildhall, museum, fire station and anatomical theatre, among others. The Waag is the oldest remaining non-religious building in Amsterdam. The building has held rijksmonument status since 1970. The Waag is depicted in Rembrandt 's 1632 painting The Anatomy Lesson of Dr. Nicolaes Tulp.
Originally, the building was one of the gates in the city wall, the Sint Antoniespoort (Saint Anthony's Gate). The gate was located at the end of the Zeedijk dike, which continued beyond the gate as the Sint Antoniesdijk. After the Lastage area was added to the city in the 16th century, the Sint Antoniesdijk became the Sint Antoniesbreestraat and a new Sint Antoniespoort city gate was built near the Hortus Botanicus.
The city gate was part of the medieval city walls along the moat formed by the current Singel canal and the canals of the Kloveniersburgwal and the Geldersekade. These walls were constructed during the period 1481-1494 and consisted of defensive towers and city gates connected by walls of brick with a natural stone pediment. All that remains of the walls is some sandstone in the Geldersekade canal wall. The only remains of the city gates are the Waag and part of the Regulierspoort gate, which is now the bottom half of the Munttoren tower. The Schreierstoren is the only remaining defensive tower.
The building was built of brick, with some ornamental elements made out of limestone quarried in Gobertange in present-day Belgium. Originally, the gate consisted of a building with two towers on the inner (city) side, as well as a front gate with two towers on the outer (moat) side. Between the front gate and main gate, there was a small square covering a subterraneous sluice gate. The walls of the towers are almost 2 metres thick. The oldest gable stone in Amsterdam adorns the facade of the tower at the corner of Zeedijk and Geldersekade.
In the first half of the 19th century, punishments were carried out in front of the building. There was even a guillotine. In the 20th century, the building was used primarily as a museum. It was the original location of the Amsterdams Historisch Museum (now Amsterdam Museum) as well as the Joods Historisch Museum (Jewish Historical Museum).
In the period 1989-1994, the building was not used and stood empty. Eventually the building was handed over to a foundation, Stichting Centrum De Waag, which commissioned Philippe Starck to design a glass extension that would have required part of the outer wall to be demolished. However, the foundation went bankrupt before these plans were carried out. On 20 September 1991, local residents and preservationists opened the disused building to the press and the public. A general sense of dismay, which also resounded in the city council, led to the appointment of a commission of experts, which proposed to have the building restored under the guidance of an architect with expert knowledge of medieval construction and foundation. Walter Kramer was appointed to lead the restoration. During restoration, the cellars (which had been filled in) were reopened, an a wooden awning was added to the eastern facade. The paving around the building was changed so that de Waag again became the centre point on Nieuwmarkt square.
Waag Society, a foundation that aims to foster experimentation with new technologies, art and culture, is housed on the upper floors. The ground floor is now a café and restaurant.