The Amsterdam Museum, until 2011 called the Amsterdams Historisch Museum, is a museum about the history of Amsterdam. Since 1975, it is located in the old city orphanage between Kalverstraat and Nieuwezijds Voorburgwal. The museum opened in 1926 in the Waag, a 15th-century building on Nieuwmarkt square. It has been located since 1975 in a building that was originally constructed in 1580 as Amsterdam's orphanage. The building was extended by Hendrick and his son Pieter de Keyser before Jacob van Campen rebuilt it in 1634. The orphanage continued in this building until 1960