The I amsterdam City Cardprovides free and discounted admissions to many of Amsterdam's top museums (but not the Anne Frank House or Rijksmuseum), plus a free canal ride, free use of public transport (excluding trains), various giveaways, and a 25% discount on attractions and restaurants—savings can be substantial. It also includes some attractions outside of Amsterdam, including the Zaanse Schans, Zuiderzeemuseum in Enkhuizen, Amsterdam Castle Muiderslot, and attractions in Haarlem and Volendam. A 24-hour card costs €57, 48 hours costs €67, 72 hours €77, and 96 hours €87. It can be purchased online in advance, with home delivery worldwide, or at the I amsterdam Store (Centraal Station), I amsterdam Visitor Information Centres (Centraal Station, Schiphol Airport), branches of the GVB at various stations, and at some hotels and museums.
If you are here for a few more days or intend to visit other parts of the Netherlands, a Museumkaart (museum card) might offer better value. This gives you free entry to over 400 museums throughout the country for a year, including the top draws in Amsterdam. It is available, upon showing ID, at participating museums for €59.90.